Treat # in color literals as a separate token

grammar.js

@@ -249,7 +249,7 @@ module.exports = grammar({
       $.call_expression
     )),
 
-    color_value: $ => /#[0-9a-fA-F]{3,8}/,
+    color_value: $ => seq('#', token.immediate(/[0-9a-fA-F]{3,8}/)),
 
     string_value: $ => token(choice(
       seq("'", /([^'\n]|\\(.|\n))*/, "'"),

src/grammar.json

@@ -1126,8 +1126,20 @@
       }
     },
     "color_value": {
-      "type": "PATTERN",
-      "value": "#[0-9a-fA-F]{3,8}"
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "#"
+        },
+        {
+          "type": "IMMEDIATE_TOKEN",
+          "content": {
+            "type": "PATTERN",
+            "value": "[0-9a-fA-F]{3,8}"
+          }
+        }
+      ]
     },
     "string_value": {
       "type": "TOKEN",