Remove custom colors and rely on inbuilt colors for better theme support

Author: anshkathuria

package.json

@@ -674,35 +674,6 @@
                     }
                 }
             }
-        ],
-        "colors": [
-            {
-                "id": "problems.difficulty.badge.easy",
-                "description": "Color for easy problems badge",
-                "defaults": {
-                    "light": "#00b8a3",
-                    "dark": "#00b8a3",
-                    "highContrast": "#00b8a3"
-                }
-            },
-            {
-                "id": "problems.difficulty.badge.medium",
-                "description": "Color for medium level problems badge",
-                "defaults": {
-                    "light": "#ffc01e",
-                    "dark": "#ffc01e",
-                    "highContrast": "#ffc01e"
-                }
-            },
-            {
-                "id": "problems.difficulty.badge.hard",
-                "description": "Color for hard problems badge",
-                "defaults": {
-                    "light": "#ff375f",
-                    "dark": "#ff375f",
-                    "highContrast": "#ff375f"
-                }
-            }
         ]
     },
     "scripts": {

src/explorer/LeetCodeTreeItemDecorationProvider.ts

@@ -9,9 +9,9 @@ export class LeetCodeTreeItemDecorationProvider implements FileDecorationProvide
     };
 
     private readonly ITEM_COLOR: { [key: string]: ThemeColor } = {
-        easy: new ThemeColor("problems.difficulty.badge.easy"),
-        medium: new ThemeColor("problems.difficulty.badge.medium"),
-        hard: new ThemeColor("problems.difficulty.badge.hard"),
+        easy: new ThemeColor("charts.green"),
+        medium: new ThemeColor("charts.yellow"),
+        hard: new ThemeColor("charts.red"),
     };
 
     public provideFileDecoration(uri: Uri): ProviderResult<FileDecoration>  {