Mob/mog Dresses

Greens, blues, and purples are generally good, "go-to" hues that compliment a variety of skin tones and figures.

Some examples:
A "eucalyptus" shade of green.
Dark or deep teal

Hunter green
Slate blue

Navy blue
A deep lavender or wisteria
Darker shades of purple ranging from those closer to "royal", or an "eggplant".

I had a late summer wedding where my husband wore a suit in a deep blue shade similar to Navy, mom wore Navy blue, my father wore a darker, charcoal gray suit, my husband's aunt wore a "Victoria Purple" dress from Catherine's, my husbands uncle wore a black suit with a lavender shirt, my bridesmaids were in Mori Lee moss green dresses, the groomsmen wore light gray suits with ties to match the bridesmaid dresses.

Maybe some other people will add some color recommendations. Just consider though that you should only be giving suggestions not required colors for them. Mainly just do so if they are interested in fitting in with your theme colors. Otherwise, they will not typically be in pictures with the bridesmaids --which could be the greatest color clash.