How to protect transparent areas

[soioartist]

Dear community
perhaps a rather simple question - how is it possible to protect transparent areas in a layer (like in photoshop)? i would like to recolorise shapes with a different color be it manually with a brush or with the filling shape tool. in PS you have a checkbox to protect transparent areas of a layer.
best regards
simon

[slowtiger]

See that little mask icon on top of the layer names in your timeline? Click the button below that in the layer you want to use as mask.

[soioartist]

Hi Slowtiger
many thanks for the hint - works perfectly (of course).
have a nice day.