For controls, especially image controls, it is very nice to have such filters:

• Colorize R/G/B/Probably Alpha too?
• Hue/Saturation shift
• Brightness/Darken
• Blur
• Mirror Vertically/Horizontally

And blending mode like usual image editing software:

• Normal
• Addition
• Substract
• Multiply
• Overlay
• Soft Light

or more... I think I want transfer Alpha/transparency value from control/diplay A to B is also a good addition IMO.

Just a very wild wish!