docs: @ColorInt public static int decreaseRgbChannels(Context context,
                                                      @ColorRes int res, float percent) {
          int c = resolveColor(res, context);
  
          // reduce rgb channel values to produce box shadow effect
          int red = (Color.red(c));
          red -= (red * percent);
          red = red > 0 ? red : 0;
  
          int green = (Color.green(c));
          green -= (green * percent);
          green = green > 0 ? green : 0;
  
          int blue = (Color.blue(c));
          blue -= (blue * percent);
          blue = blue > 0 ? blue : 0;
  
          return Color.argb(Color.alpha(c), red, green, blue);
      }