@Override
    public void setPercent(float percent) {
        if (percent < .4f)
            return;
        percent = (percent - .4f) / .6f;
        setAlpha((int) (MAX_ALPHA * percent));
        showArrow(true);
        float strokeStart = ((percent) * .8f);
        setStartEndTrim(0f, Math.min(MAX_PROGRESS_ANGLE, strokeStart));
        setArrowScale(Math.min(1f, percent));
        float rotation = percent < .8f ? 0 : (percent - .8f) / .2f * .25f;
        setProgressRotation(rotation);
    }
Update the background color of the circle image view.
library/src/main/java/com/baoyz/widget/MaterialDrawable.java