The Magpul OD furniture to me looks better than the FDE. However, as I posted earlier, I went with FDE because of a specific hunting need.

Unique colors for 223/5.56 and a 300 BO would make a lot of sense to help prevent a kaboom by putting a 300 BO in a 223/5.56 chamber. It could be completely different colors for all furniture on separate guns, or at least matching mags and forend for a 300 upper. Perhaps black for 223/5/56 and OD for 300 BO.

I ran into a similar problem years ago when shooting with friends. They all had 7.62x39 AK's, while mine was .223/5.56. The mags would interchange. I ran a piece of red automotive pinstripping tape down one of the embossed rib valleys on both sides of my mags so they could be identified easily.

Another way to separate 223/5/56 from 300 BO is to use completely different mags. Like 30's for 223/5/56 and 20's for 300 BO, or plastic for one and metal for the other, etc. Magpul also makes the latest gen mags with dot matrix embossing so they can be marked 300, etc., by putting a drop of paint in the divots.