[Reijii]

это был путь к разделу в хелпе, правда в 8, вот что там

The UIScrollBar component supports the following styles:
themeColor
- Halo The base color scheme of a component. Possible values are "haloGreen", "haloBlue", and "haloOrange". The default value is "haloGreen".

scrollTrackColor
- The background color for the scroll track.The default value is 0xCCCCCC (light gray).

symbolColor
- The color of the up and down scroll arrows. The default value is 0x000000 (black).

symbolDisabledColor
- The color of the up and down scroll arrows in a disabled scroll bar. The default value is 0x848384 (dark gray).

про сами стили почитай в pdf, про метод setStyle.