Have you given any thought yet to regimental flags? How will each unit's colors be connected to their flags (or wiil they be)? This is something to think about now. Also, are you using any sort of "theme" for your units? You certainly don't have to . . . but if you do, some thoughts on the theme (whatever it might be) can inspire your choices for both uniforms and flags.
Only very vague consideration, regarding the unit flags. I'm thinking of toying with some coats of arms involving a blue wolf (the translation of Blauerwolf, the family name of the rulers), but beyond that I've not yet considered.
The colors being connected to the flags is a very good question. I like this idea. I'll have to play with some possibilities.
There's not presently any theme for the units. The green with orange combination was inspired by one of the French Dragoon uniforms I intend to include among my Napoleonic regiments. I thought it'd be fitting for a Jager unit, as looking through the 7YW plates on the Wargames etc site seems to suggest that it was popular to dress Jagers in a nice camoflaguing green combined with such incredibly bright facing colors a blind man couldn't miss. ;) So the green with orange seemed like a good combo that would be somewhat distinctive.
I also admit that the Guards uniform started because I was looking at my bottles of paint and there's this Andrea Blue that was in the Napoleonics set from Vallejo, but is not in any of my presently intended Napoleonic units. Seemed a shame to let it go to waste, so I tried the color on the templates and rather liked it. I'm not sure if I'm sticking with the white facings or not. They do provide an interesting icy sort of look with that blue, if it paints like it renders on the template.