Add missing sub feature to CSS color type (#27479)

Author: Elchi3

css/types/color.json

@@ -1670,6 +1670,48 @@
               }
             }
           }
+        },
+        "transparent": {
+          "__compat": {
+            "tags": [
+              "web-features:color"
+            ],
+            "support": {
+              "chrome": {
+                "version_added": "1"
+              },
+              "chrome_android": "mirror",
+              "edge": {
+                "version_added": "12"
+              },
+              "firefox": {
+                "version_added": "1"
+              },
+              "firefox_android": "mirror",
+              "ie": {
+                "version_added": "3"
+              },
+              "oculus": "mirror",
+              "opera": {
+                "version_added": "3.5"
+              },
+              "opera_android": {
+                "version_added": "10.1"
+              },
+              "safari": {
+                "version_added": "1"
+              },
+              "safari_ios": "mirror",
+              "samsunginternet_android": "mirror",
+              "webview_android": "mirror",
+              "webview_ios": "mirror"
+            },
+            "status": {
+              "experimental": false,
+              "standard_track": true,
+              "deprecated": false
+            }
+          }
         }
       }
     }