added deprecated fade method

packages/material-ui/src/styles/colorManipulator.d.ts

@@ -13,6 +13,11 @@ export function recomposeColor(color: ColorObject): string;
 export function getContrastRatio(foreground: string, background: string): number;
 export function getLuminance(color: string): number;
 export function emphasize(color: string, coefficient?: number): string;
+/**
+ * @deprecated
+ * Use `import { alpha } from '@material-ui/core/styles'` instead.
+ */
+export function fade(color: string, value: number): string;
 export function alpha(color: string, value: number): string;
 export function darken(color: string, coefficient: number): string;
 export function lighten(color: string, coefficient: number): string;

packages/material-ui/src/styles/colorManipulator.js

@@ -237,6 +237,36 @@ export function alpha(color, value) {
   return recomposeColor(color);
 }
 
+let warnedOnce = false;
+
+/**
+ * Set the absolute transparency of a color.
+ * Any existing alpha values are overwritten.
+ *
+ * @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
+ * @param {number} value - value to set the alpha channel to in the range 0 -1
+ * @returns {string} A CSS color string. Hex input values are returned as rgb
+ *
+ * @deprecated
+ * Use `import { alpha } from '@material-ui/core/styles'` instead.
+ */
+export function fade(color, value) {
+  if (process.env.NODE_ENV !== 'production') {
+    if (!warnedOnce) {
+      warnedOnce = true;
+      console.error(
+        [
+          'Material-UI: The `fade` color utility was renamed to `alpha` to better describe its functionality.',
+          '',
+          "You should use `import { alpha } from '@material-ui/core/styles'`",
+        ].join('\n'),
+      );
+    }
+  }
+
+  return alpha(color, value);
+}
+
 /**
  * Darkens a color.
  * @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla(), color()