I just downloaded a bunch of brushes on GIMP, and when i try to add color to them, it says i can only add color to RGB color layers.
how can i fix this so i can add color?
An RGB layer is colour. Add a layer that's RGB and try colouring on that.
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did u save them in your brush folder? not as a pic, but as a brush? look at youtube tut's, im too lazy to explain
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Hit File>New, open Advanced Options, make sure color space says RGB Color.