Well I mainly use the Odyssey uniforms because that is what Starfleet using in the current year - though I use the Terran Empire sleeveless version because my character being an Andorian-Aenar hybrid often overheats outside of very cool air conditioned rooms! The only thing I do a bit different is that I have the Starfleet Intelligence colour for my career marking because my OC is in Starfleet Intelligence and mainly works in those circles because he often inhabits the 'grey areas' in the Starfleet code as it were.
That said I absolutely love the look of the Dyson Scientist uniform but it is just so badly done and pixelated that is comes out looking really really poor and ugly up close - really disappointed in it as it looks nothing like the promotional material for it did =/
I use the M.A.C.O. uniform on my Captain and away team. I use the standard Odyssey uniforms for the rest of my bridge officers with the blue, red and yellow of science/medical, command/tactical and engineering/operations respectively.
I am wearing red for now as I am an Admiral and am following 25th century Star Fleet guidelines. I am using the Odyessy uniforms. May consider switching to white, though.
red command all the way for me
I prefer the ds9 uniform colors (red upper command ) of the uniform black color in the middle and the ds9 badge on chest .
Usually I use red, but sometimes I use black and white. (I don't play the game, but I'm still a fan.)