diff --git a/src/builtin/color/rgb.rs b/src/builtin/color/rgb.rs
index 7bf0231..f37b204 100644
--- a/src/builtin/color/rgb.rs
+++ b/src/builtin/color/rgb.rs
@@ -12,7 +12,13 @@ use crate::selector::Selector;
 use crate::unit::Unit;
 use crate::value::{Number, Value};
 
-fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResult<Value> {
+/// name: Either `rgb` or `rgba` depending on the caller
+fn inner_rgb(
+    name: &'static str,
+    mut args: CallArgs,
+    scope: &Scope,
+    super_selector: &Selector,
+) -> SassResult<Value> {
     if args.is_empty() {
         return Err(("Missing argument $channels.", args.span()).into());
     }
@@ -42,7 +48,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
                 let red = channels.pop().unwrap();
                 return Ok(Value::Ident(
                     format!(
-                        "rgb({}, {}, {})",
+                        "{}({}, {}, {})",
+                        name,
                         red.to_css_string(args.span())?,
                         green.to_css_string(args.span())?,
                         v.to_css_string(args.span())?
@@ -66,12 +73,13 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
             Some(v) if v.is_special_function() => {
                 let string = match channels.pop() {
                     Some(red) => format!(
-                        "rgb({}, {}, {})",
+                        "{}({}, {}, {})",
+                        name,
                         red.to_css_string(args.span())?,
                         v.to_css_string(args.span())?,
                         blue
                     ),
-                    None => format!("rgb({} {})", v.to_css_string(args.span())?, blue),
+                    None => format!("{}({} {})", name, v.to_css_string(args.span())?, blue),
                 };
                 return Ok(Value::Ident(string, QuoteKind::None));
             }
@@ -91,7 +99,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
             Some(v) if v.is_special_function() => {
                 return Ok(Value::Ident(
                     format!(
-                        "rgb({}, {}, {})",
+                        "{}({}, {}, {})",
+                        name,
                         v.to_css_string(args.span())?,
                         green,
                         blue
@@ -119,7 +128,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
                 let alpha = arg!(args, scope, super_selector, 1, "alpha");
                 return Ok(Value::Ident(
                     format!(
-                        "rgb({}, {})",
+                        "{}({}, {})",
+                        name,
                         v.to_css_string(args.span())?,
                         alpha.to_css_string(args.span())?
                     ),
@@ -150,7 +160,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
             v if v.is_special_function() => {
                 return Ok(Value::Ident(
                     format!(
-                        "rgb({}, {}, {}, {})",
+                        "{}({}, {}, {}, {})",
+                        name,
                         color.red(),
                         color.green(),
                         color.blue(),
@@ -186,7 +197,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
                 let green = arg!(args, scope, super_selector, 1, "green");
                 let blue = arg!(args, scope, super_selector, 2, "blue");
                 let mut string = format!(
-                    "rgb({}, {}, {}",
+                    "{}({}, {}, {}",
+                    name,
                     v.to_css_string(args.span())?,
                     green.to_css_string(args.span())?,
                     blue.to_css_string(args.span())?
@@ -225,7 +237,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
             v if v.is_special_function() => {
                 let blue = arg!(args, scope, super_selector, 2, "blue");
                 let mut string = format!(
-                    "rgb({}, {}, {}",
+                    "{}({}, {}, {}",
+                    name,
                     red,
                     v.to_css_string(args.span())?,
                     blue.to_css_string(args.span())?
@@ -262,8 +275,13 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
                     .into())
             }
             v if v.is_special_function() => {
-                let mut string =
-                    format!("rgb({}, {}, {}", red, green, v.to_css_string(args.span())?);
+                let mut string = format!(
+                    "{}({}, {}, {}",
+                    name,
+                    red,
+                    green,
+                    v.to_css_string(args.span())?
+                );
                 if !args.is_empty() {
                     string.push_str(", ");
                     string.push_str(
@@ -303,7 +321,8 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
             }
             v if v.is_special_function() => {
                 let string = format!(
-                    "rgb({}, {}, {}, {})",
+                    "{}({}, {}, {}, {})",
+                    name,
                     red,
                     green,
                     blue,
@@ -325,317 +344,12 @@ fn rgb(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResu
     }
 }
 
-fn rgba(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResult<Value> {
-    if args.is_empty() {
-        return Err(("Missing argument $channels.", args.span()).into());
-    }
+fn rgb(args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResult<Value> {
+    inner_rgb("rgb", args, scope, super_selector)
+}
 
-    if args.len() == 1 {
-        let mut channels = match arg!(args, scope, super_selector, 0, "channels") {
-            Value::List(v, ..) => v,
-            _ => return Err(("Missing argument $channels.", args.span()).into()),
-        };
-
-        if channels.len() > 3 {
-            return Err((
-                format!(
-                    "Only 3 elements allowed, but {} were passed.",
-                    channels.len()
-                ),
-                args.span(),
-            )
-                .into());
-        }
-
-        let blue = match channels.pop() {
-            Some(Value::Dimension(n, Unit::None)) => n,
-            Some(Value::Dimension(n, Unit::Percent)) => (n / Number::from(100)) * Number::from(255),
-            Some(v) if v.is_special_function() => {
-                let green = channels.pop().unwrap();
-                let red = channels.pop().unwrap();
-                return Ok(Value::Ident(
-                    format!(
-                        "rgba({}, {}, {})",
-                        red.to_css_string(args.span())?,
-                        green.to_css_string(args.span())?,
-                        v.to_css_string(args.span())?
-                    ),
-                    QuoteKind::None,
-                ));
-            }
-            Some(v) => {
-                return Err((
-                    format!("$blue: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-            None => return Err(("Missing element $blue.", args.span()).into()),
-        };
-
-        let green = match channels.pop() {
-            Some(Value::Dimension(n, Unit::None)) => n,
-            Some(Value::Dimension(n, Unit::Percent)) => (n / Number::from(100)) * Number::from(255),
-            Some(v) if v.is_special_function() => {
-                let string = match channels.pop() {
-                    Some(red) => format!(
-                        "rgba({}, {}, {})",
-                        red.to_css_string(args.span())?,
-                        v.to_css_string(args.span())?,
-                        blue
-                    ),
-                    None => format!("rgba({} {})", v.to_css_string(args.span())?, blue),
-                };
-                return Ok(Value::Ident(string, QuoteKind::None));
-            }
-            Some(v) => {
-                return Err((
-                    format!("$green: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-            None => return Err(("Missing element $green.", args.span()).into()),
-        };
-
-        let red = match channels.pop() {
-            Some(Value::Dimension(n, Unit::None)) => n,
-            Some(Value::Dimension(n, Unit::Percent)) => (n / Number::from(100)) * Number::from(255),
-            Some(v) if v.is_special_function() => {
-                return Ok(Value::Ident(
-                    format!(
-                        "rgba({}, {}, {})",
-                        v.to_css_string(args.span())?,
-                        green,
-                        blue
-                    ),
-                    QuoteKind::None,
-                ));
-            }
-            Some(v) => {
-                return Err((
-                    format!("$red: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-            None => return Err(("Missing element $red.", args.span()).into()),
-        };
-
-        let color = Color::from_rgba(red, green, blue, Number::one());
-
-        Ok(Value::Color(Box::new(color)))
-    } else if args.len() == 2 {
-        let color = match arg!(args, scope, super_selector, 0, "color") {
-            Value::Color(c) => c,
-            v if v.is_special_function() => {
-                let alpha = arg!(args, scope, super_selector, 1, "alpha");
-                return Ok(Value::Ident(
-                    format!(
-                        "rgba({}, {})",
-                        v.to_css_string(args.span())?,
-                        alpha.to_css_string(args.span())?
-                    ),
-                    QuoteKind::None,
-                ));
-            }
-            v => {
-                return Err((
-                    format!("$color: {} is not a color.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        let alpha = match arg!(args, scope, super_selector, 1, "alpha") {
-            Value::Dimension(n, Unit::None) => n,
-            Value::Dimension(n, Unit::Percent) => n / Number::from(100),
-            v @ Value::Dimension(..) => {
-                return Err((
-                    format!(
-                        "$alpha: Expected {} to have no units or \"%\".",
-                        v.to_css_string(args.span())?
-                    ),
-                    args.span(),
-                )
-                    .into())
-            }
-            v if v.is_special_function() => {
-                return Ok(Value::Ident(
-                    format!(
-                        "rgba({}, {}, {}, {})",
-                        color.red(),
-                        color.green(),
-                        color.blue(),
-                        v.to_css_string(args.span())?
-                    ),
-                    QuoteKind::None,
-                ));
-            }
-            v => {
-                return Err((
-                    format!("$alpha: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        Ok(Value::Color(Box::new(color.with_alpha(alpha))))
-    } else {
-        let red = match arg!(args, scope, super_selector, 0, "red") {
-            Value::Dimension(n, Unit::None) => n,
-            Value::Dimension(n, Unit::Percent) => (n / Number::from(100)) * Number::from(255),
-            v @ Value::Dimension(..) => {
-                return Err((
-                    format!(
-                        "$red: Expected {} to have no units or \"%\".",
-                        v.to_css_string(args.span())?
-                    ),
-                    args.span(),
-                )
-                    .into())
-            }
-            v if v.is_special_function() => {
-                let green = arg!(args, scope, super_selector, 1, "green");
-                let blue = arg!(args, scope, super_selector, 2, "blue");
-                let mut string = format!(
-                    "rgba({}, {}, {}",
-                    v.to_css_string(args.span())?,
-                    green.to_css_string(args.span())?,
-                    blue.to_css_string(args.span())?
-                );
-                if !args.is_empty() {
-                    string.push_str(", ");
-                    string.push_str(
-                        &arg!(args, scope, super_selector, 3, "alpha")
-                            .to_css_string(args.span())?,
-                    );
-                }
-                string.push(')');
-                return Ok(Value::Ident(string, QuoteKind::None));
-            }
-            v => {
-                return Err((
-                    format!("$red: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        let green = match arg!(args, scope, super_selector, 1, "green") {
-            Value::Dimension(n, Unit::None) => n,
-            Value::Dimension(n, Unit::Percent) => (n / Number::from(100)) * Number::from(255),
-            v @ Value::Dimension(..) => {
-                return Err((
-                    format!(
-                        "$green: Expected {} to have no units or \"%\".",
-                        v.to_css_string(args.span())?
-                    ),
-                    args.span(),
-                )
-                    .into())
-            }
-            v if v.is_special_function() => {
-                let blue = arg!(args, scope, super_selector, 2, "blue");
-                let mut string = format!(
-                    "rgba({}, {}, {}",
-                    red,
-                    v.to_css_string(args.span())?,
-                    blue.to_css_string(args.span())?
-                );
-                if !args.is_empty() {
-                    string.push_str(", ");
-                    string.push_str(
-                        &arg!(args, scope, super_selector, 3, "alpha")
-                            .to_css_string(args.span())?,
-                    );
-                }
-                string.push(')');
-                return Ok(Value::Ident(string, QuoteKind::None));
-            }
-            v => {
-                return Err((
-                    format!("$green: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        let blue = match arg!(args, scope, super_selector, 2, "blue") {
-            Value::Dimension(n, Unit::None) => n,
-            Value::Dimension(n, Unit::Percent) => (n / Number::from(100)) * Number::from(255),
-            v @ Value::Dimension(..) => {
-                return Err((
-                    format!(
-                        "$blue: Expected {} to have no units or \"%\".",
-                        v.to_css_string(args.span())?
-                    ),
-                    args.span(),
-                )
-                    .into())
-            }
-            v if v.is_special_function() => {
-                let mut string =
-                    format!("rgba({}, {}, {}", red, green, v.to_css_string(args.span())?);
-                if !args.is_empty() {
-                    string.push_str(", ");
-                    string.push_str(
-                        &arg!(args, scope, super_selector, 3, "alpha")
-                            .to_css_string(args.span())?,
-                    );
-                }
-                string.push(')');
-                return Ok(Value::Ident(string, QuoteKind::None));
-            }
-            v => {
-                return Err((
-                    format!("$blue: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        let alpha = match arg!(
-            args,
-            scope,
-            super_selector,
-            3,
-            "alpha" = Value::Dimension(Number::one(), Unit::None)
-        ) {
-            Value::Dimension(n, Unit::None) => n,
-            Value::Dimension(n, Unit::Percent) => n / Number::from(100),
-            v @ Value::Dimension(..) => {
-                return Err((
-                    format!(
-                        "$alpha: Expected {} to have no units or \"%\".",
-                        v.to_css_string(args.span())?
-                    ),
-                    args.span(),
-                )
-                    .into())
-            }
-            v if v.is_special_function() => {
-                let string = format!(
-                    "rgba({}, {}, {}, {})",
-                    red,
-                    green,
-                    blue,
-                    v.to_css_string(args.span())?
-                );
-                return Ok(Value::Ident(string, QuoteKind::None));
-            }
-            v => {
-                return Err((
-                    format!("$alpha: {} is not a number.", v.to_css_string(args.span())?),
-                    args.span(),
-                )
-                    .into())
-            }
-        };
-        Ok(Value::Color(Box::new(Color::from_rgba(
-            red, green, blue, alpha,
-        ))))
-    }
+fn rgba(args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResult<Value> {
+    inner_rgb("rgba", args, scope, super_selector)
 }
 
 fn red(mut args: CallArgs, scope: &Scope, super_selector: &Selector) -> SassResult<Value> {