The point is though is that we don't know the vast majority of regimental uniforms. This site lists most of the known units that fought in the Civil Wars:http://wiki.bcw-project.org/start
You then have contradictory evidence, for example the Earl of Manchester's regiment in one source is listed in red faced green and another as green faced red, could well have been a mixture of the two. Uniforms as well were guidelines, in the field that could well easily break down and with precious few pictorial sources from the era, not to mention literary sources are fragmented and many were lost (the records of the King's Oxford Parliament were lost when the city fell), then it is hard to know for sure.
We probably have definitive evidence for about twenty or thirty English regiments out of hundreds, the rest is pure conjecture although fortunately we only need a dozen or so for the mod.
Thanks for the ebooks although I have most of them already (I have just studied the Civil Wars at University so I have already trawled through dozens of books on the subject!) The best one I found is the book by Philip Haythornthwaite, a little old now but still very detailed with some lovely colour plates. By the way I wish I had had this sooner, I spent nearly twenty pounds on the rule book for Pike and Shotte last Christmas!
EDIT: looking good, nice the see the sash looks better. I believe that chap is an officer, sergeants whilst not as poor as the common soldier would probably be more in the uniform of their regiment although if they had money then you never know what they might wear (if they had money they probably would be an officer already!). I think the chaps tunic might be a little too long and the lace to tie it up should be a little more pronounced. Then again, I am being picky, I haven't a clue about modelling and texturing so have no idea about the difficulties of creating such a thing!