[Feature request] Missing Laf colour properties

[d.healey]

I've spent the last couple of hours trying to implement these myself but failed :(

• drawScrollbar, use the colour properties of the viewport or floating tile.

• drawPopupMenuBackground, use the combo box colour properties (would also be good if the base colour was transparent so we could do rounded corners, currently it's solid white).

If anyone can think of any other missing colour properties please add them to this thread.

[DabDab]

Label laf is also necessary. I guess only Laf is possible via css. No traditional LAF is supported for Label.