Color filters to blend with background bitmap

The color filters I'm taking about is overlay, multiply etc. that you choose in the paint tab. I want them to work with the background bitmap you set in root.

I have really good ideas for wallpapers equipped with this ability. This can give some beautiful colors, but right now this only works with an image in the same overlap group. This is not optimal of you want a clock for example to blend with the whole BG.