This is probably a very easy question, but I am stumped.
I am trying to edit a png. I select a colour with the "Select by color" tool, change the fill colour to red
ff0000, or 255,0,0, but when I click the selection to fill, it looks brown.
Other colours also act this way: blue -> purple, yellow -> light brown, etc. White seems to fill correctly.
So, what am I doing wrong? I'm thinking it has to do with the file format or some underlying filter.