Update color function

assets.json

@@ -1,3 +1,3 @@
 {
-    "version": 1675955478084
+    "version": 1682069627576
 }

assets/styles/tools/_functions.scss

@@ -149,14 +149,12 @@ $context: 'frontend' !default;
 // }
 // ```
 //
-// @param  {string} $key - The color key in $colors
-// @return {function<string>} in hexadecimal
+// @param  {string} $key - The color key in $colors.
+// @return {color}
+
 @function color($key) {
-    @if map-has-key($colors, $key) {
-        @return map-get($colors, $key);
+    @if not map-has-key($colors, $key) {
+        @error "Unknown '#{$key}' in $colors.";
     }
-
-    @warn "Unkown '#{$key}' in $colors.";
-
-    @return null;
+    @return map-get($colors, $key);
 }