I'm trying to create a framework that takes care of windows, buttons, checkboxes and things like that, but I'm having some problems. At this point I'm trying to build an in-game window by first rendering the frame that consists of textures and then fill the rest of the window with a colored rectangle. The problem that I'm having is that the colors are off completely and also that the color of a non-textured colored rectangle changes the "hue" (if you will) of the colors of textures. When I render both the frame and the rectangle, the rectangle's colors change the hue of the frame, but when I remove the rectangle from the code, the frame has the colors that I want it to have.
The image shows these 2 scenarios:
The window to the left is the scenario where I don't render the colored rectangle inside the window and the frame has the colors that I want it to have.
The window to the right is the scenario where I render the colored rectangle inside the window, but the frame changes its colors after the color of the rectangle (it's hard to see the frame, but it's there)
This is the code I use in order to render the colored rectangle: