Merge pull request #15695 from guncha/patch-1

[color] Add a missing rgb() method

types/color/index.d.ts

@@ -66,6 +66,7 @@ declare namespace Color {
         keyword(): string | undefined;
         hex(color: string): Color;
         hex(): string;
+        rgb(): Color;
         rgbNumber(): number;
         luminosity(): number;
         contrast(color: Color): number;