As described in the most recent journal I made myself a winter themed icon, using the free icon base pack by Fivel. I made new hair, to suit my catman better. I didn't manage to make it anything like the original style though lol.
There was one thing about it though... Some layers had "lock" written next to the opacity level. I have no idea how to enable or disable that, but it seems to be something very useful as those layers had some kind of automatic masking to them (which made fixing some holes in the color layer a PITA). I ended up getting rid of the "lock" by merging an empty layer with the one of interest... I'm sure there's a better way but I didn't seem to find it...