Make subcategory colors override main category

Right now, (1.6.5) if I have nested categories (or 'subcategories'), the main category color is used on the event calendar.

Thus:
Free Events (Green)
Introductory Course (Red)

The "Introductory Course" will show up as Green, not Red.

Please consider making the subcategory color selection as a "higher priority" color and use that if it has been set.

Actually, looking at event creation, I believe my request wasn't complete.

Additionally, the color should always be derived from the main (primary) selection.

The alternative would be to construct a multiple colored block, one for each color, but that's too elaborate and probably of little value.

Additionally, please allow the ability to set a color for a single event, which would override all other color selections.