Two comments.
First, your pictures don\'t really need a new camera; you just need to do some color correcting with Photoshop or GIMP. GIMP is free, so you should really check into that if you want to get more feedback on your future stuff. A google search should locate a download site no problem.
My biggest gripe about the actual paintjob is the neatness, especially on the chest. I would not suggest that you use maroon to shade that brown. If you do, however, the \"width\" of the crimson line should be uniform at all times. You have some parts of the chest where the crimson color invades some of the brown surface, and it appears sloppy. In the center of the chest, also, the brown runs into the recess, giving the impression of a lack of control. The Tau are a race of perfect lines and angles, all of which demands a very controlled style.
On the positive side, you seem to understand the highlighting of the surfaces. You use them sparingly, and where they will have the most effect. Combine this with neater shading and you\'re going to have a kick-bum army.