Update colors for the round scroll bar.

    private static final int MAX_SCROLLBAR_ANGLE_SWIPE = 16;

    private static final int MIN_SCROLLBAR_ANGLE_SWIPE = 6;

    private static final float WIDTH_PERCENTAGE = 0.02f;

    private static final int DEFAULT_THUMB_COLOR = 0xFF757575;

    private static final int DEFAULT_TRACK_COLOR = 0x21FFFFFF;

    private static final int DEFAULT_THUMB_COLOR = 0x4CFFFFFF;

    private static final int DEFAULT_TRACK_COLOR = 0x26FFFFFF;

    private final Paint mThumbPaint = new Paint();

    private final Paint mTrackPaint = new Paint();