Teamcolour (as far as the texture is concerned) is in the alpha channel of the texture. If the model is supposed to have team colour but doesn't, it most likely means that you've saved the file as something that doesn't support alpha or at the wrong number of pixels/bit. Saving as .tga or as 32bit .bmp from Photoshop will preserve alpha channels, saving as .jpeg will not. I'm not sure about GIMP, I've heard that it has difficulties with alpha.