SDL程序中的颜色已关闭

I am currently working on a very simple game using a pure C approach with SDL (and its official extra libraries such as SDL_image) and OpenGL. Right now though I've hit a bit of a stumbling block and I have no idea why it is doing this: the colors are all off when drawn. I am running the program on a Mac currently, but if I remember correctly when I run it in Windows the colors are closer to being correct, but there are still some odd things happening (such as a pure white polygon drawing as yellow).I am currently working on a very simple game us