Hmm... I like the design, though I'm not really good at drawing mech. stuff haha! As for the coloring, maybe you can add highlights? Also, I don't think the shading works well for the Brown color scheme... o__o
Epic win again man! I can only recommend that you darken the shadow tone a bit in order to make it look more three-dimensional: at the moment the contrast is a tad fine and hence not noticeable enough. Great work! (Highlights, too? XD I can see now the layer you added on the Prototype-coloured picture, after you've mentioned it, but I don't think you added it here, did you? Yellow/whitish highlights would look good on these darker shades, IMO.)
Are these guys like ... the three Extended MSes of SEED / Destiny? They're definitely reminiscent to me, though it seems like they're the 'good' guys here ...
Ah ic, will take note of that for shading improvements. As for highlights, I did try out white on a new layer (opacity 23%) for highlights, but it made the unit's surface look unnatural so I just left it out. I think its kinda justified, as a military unit would be a non-reflective matte than shiny chrome.
For the chracters, well they are a trio. And they do start out looking 'bad' at first by trying to hunt down Zero-R. But later they will be allies with the main character. has been conscripted to do character design.