Military wedding- groomsmen attire??

My FH is in the navy & will be wearing his uniform too. Same as you our colors are variants of red white & blue. We're doing navy, cream, & burgundy. The GM will be in navy suits with burgundy ties. Your GM would probably look good in black suits since it's a complimentary color to the uniform.

If he is doing dress blues and no one else in his groom party is military I say dark navy suits. Tux will be too much, black will look a little off. If you want him to shine I say dark Navy.

My FH is wearing his Blues (alphas), along with his best man. The other two guys are wearing black suits.

Grey would look really nice if you want your FH to be the only one in navy