code: public static int mixColors(int fromColor, int toColor, float toAlpha) {
          float[] fromCmyk = ScrollUtils.cmykFromRgb(fromColor);
          float[] toCmyk = ScrollUtils.cmykFromRgb(toColor);
          float[] result = new float[4];
          for (int i = 0; i < 4; i++) {
              result[i] = Math.min(1, fromCmyk[i] * (1 - toAlpha) + toCmyk[i] * toAlpha);
          }
          return 0xff000000 + (0x00ffffff & ScrollUtils.rgbFromCmyk(result));
      }
docs: Mix two colors.
  <p>{@code toColor} will be {@code toAlpha/1} percent,
  and {@code fromColor} will be {@code (1-toAlpha)/1} percent.</p>
  
  @param fromColor First color to be mixed.
  @param toColor   Second color to be mixed.
  @param toAlpha   Alpha value of toColor, 0.0f to 1.0f.
  @return Mixed color value in ARGB. Alpha is fixed value (255).