public T setHandleColorRes(@ColorRes final int colorResId) {
        handleColor = ContextCompat.getColor(getContext(), colorResId);
        setHandleColor();
        return (T)this;
    }
Provides the ability to programmatically set the color of the scrollbar handleThumb.
@param colorResId to set the handleThumb.
lib/src/main/java/com/turingtechnologies/materialscrollbar/MaterialScrollBar.java