Revert "Enable ts-strict for colorUtil.ts (#1239)"

This reverts commit c3b2697.

src/utils/colorUtil.ts

@@ -1,3 +1,4 @@
+// @ts-strict-ignore
 import { memoize } from 'lodash'
 
 type RGB = { r: number; g: number; b: number }
@@ -34,8 +35,6 @@ function rgbToHsl({ r, g, b }: RGB): HSL {
       case b:
         h = (r - g) / d + 4
         break
-      default:
-        throw new Error('NOT_REACHED')
     }
     h /= 6
   }