Not sure about Android, but in iOS this might be a bit overkill.
What we started doing since iOS 7 is to export png's with alpha transparency and color them in code. That saves us a lot of time. I.e. we define a tintColor, tapColor, warningColor, etc. and paint the assets with those colors.
Obviously if the assets has multiple colors, we color it in the png instead via Sketch/Photoshop.