Resolve #3510924 "Support for coloris"

Closes #3510924

config/schema/ui_patterns_settings.sources.schema.yml

+ui_patterns_source.color:
+  type: mapping
+  label: 'Source: Color'
+  mapping:
+    value:
+      type: color_hex
+      label: 'Color value'
+
+ui_patterns_source.coloris:
+  type: mapping
+  label: 'Source: Coloris'
+  mapping:
+    value:
+      type: string
+      label: 'Coloris value'
+      constraints:
+        Regex:
+          # See color_hex in Core.
+          pattern: '/^#[0-9a-fA-F]{6}[0-9a-fA-F]{2}?$/'
+          message: "%value is not a valid hexadecimal color with transparency."
+
 ui_patterns_source.media:
   type: mapping
   label: 'Source: Media'