The dark green AERVOE looks pretty good. I wouldn't worry about CADEX foregrips not matching your rifle's furniture colour - they don't accurately match the CF's weapons either.
I've been in contact with Dave at Imperial Engravers about having my WE receiver engraved on their CNC machine. He assures me the Colt trades that were cast in can be easily covered over. He plans to simply sandblast them out, powder coat over the resulting flat surface, then engrave in the new C7 markings. He says there will still be enough material thickness to maintain adequate strength, and after taking a critical look, I believe he's right. I wish I could find a blank receiver, but my searches have turned up empty.
BTW, Dave says his CNC operator is away until sometime in September, so I'll wait a week or two before I send my receiver in.
This is starting to look like more of a winter project anyway, as I want to install a steel bolt, aluminum nozzle, and an RA-Tech trigger group. Maybe I'll order a new upper receiver and have it powder coated to match the lower...