expose icon color property (#4248)

lib/core/icon/icon.component.ts

@@ -22,6 +22,7 @@ import {
     ChangeDetectionStrategy
 } from '@angular/core';
 import { ThumbnailService } from '../services/thumbnail.service';
+import { ThemePalette } from '@angular/material';
 
 @Component({
     selector: 'adf-icon',
@@ -35,6 +36,9 @@ export class IconComponent {
     private _value = '';
     private _isCustom = false;
 
+    @Input()
+    color: ThemePalette;
+
     get value(): string {
         return this._value;
     }