Some code would help...
Without code; a couple ideas:
Make sure you have the correct texture blending mode set to allow what you are trying to do (sorry, but I don't remember it at the moment :roll: . GL_MODULATE maybe?)
Make sure you have blending enabled (I assume you do since you can see through the texture :lol: )
Make sure you are making the texture with GL_RGBA and not just GL_RGB.
Check the texture load code and make sure you are setting the red, green, blue, and alpha chanels into the right places in the texture data (i.e. make sure it is stored red, then green, then blue, then alpha)
Does the texture work if you just put it on a quad without the glColor4f()?
If your texture has the alpha in it then glColor4f(r, g, b, 1.0f) should do it (That is the way I do it, I think :roll: )...