Since Lollipop, notification small icons are "masks" (only the alpha channel is used). I can verify this in the project I am working on: previously we had a colorful small icon, and it worked well on 4.4- devices but appeared as a white square on 5.0+ devices. (We updated the icon to fix this).
But now I see apps that manage to have colorful icons on 5.0+ devices!
How do they do it?
I realize I shouldn't even try to do that since the guidelines say the icon should be a white shape, but I am curious and would like to know how it is done.
I suspect this is related to the targetSdk
, but didn't find any resources about it.