private void setHandleColor() {
        if(indicator != null) {
            ((GradientDrawable)indicator.getBackground()).setColor(handleColor);
        }
        if(!lightOnTouch) {
            handleThumb.setBackgroundColor(handleColor);
        }
    }
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