colour properties

[dhardy]

Node has background_color and foreground_color properties. Are these required? Are they useful? Are they expected to provide an exact sRGB match?

Background colour is slightly problematic since (from my point of view) many widgets don't have a background; they simply draw on top of something else — which may or may not explicitly be a background.

In both cases, the widget tree may know nothing of the colours used, brush style, transparency or underlying surface, and may not receive any notification if any of these change.

Maybe these properties are only useful if e.g. a button has a specified foreground colour?

[mwcampbell]

We don't actually use these properties yet. When we do, we will probably only use them for text runs. And in that case, if the background is transparent, omitting the background color property is fine.