I am using Photoshop CS4.
When I paint with different colors on the same layer they don't just paint on top of one another like they should. Sometimes they show up underneath each other or paint over other colors as a transparent color. For example if I paint with red one minute and then with black, the black will show on top of the red like it should. But then if I paint with white it'll show up underneath both the red and black strokes. Then if I paint with a maroon color, it will show up between the black and white brush strokes.
I have not messed with the opacity of the brushes.
I would really appreciate any help you could give me because I have no idea how this happened.