Would this be female coloration normally? Or maybe a different locality of the same species?
N. wennerae are actually color polymorphic to their environment, they'll change colors to suit their spot when they molt. Meral spots stay constant.
I actually can't tell what that one in the photo is without seeing the front and sides, but by description of the one they own a pink N. Wennerae is one common color when they're found in deeper water. There aren't a lot of species they can do that color morph but N. wennerae fits the description as its the only gulf species that comes to mind with red coloration.
Almost all of them turn dark or light green in captivity after their first molt, they pretty much never stick to one color. I've never been successful in forcing a color, but it could be attributed to elevation even especially with pink/red color morphs which mostly come from deeper water.
Gulf/Keys/Florida you pretty much are only going to find N. wennerae, N. Oerstedii (which I haven't seen in so many years its somewhat concerning), & N. curacaoensis (very obvious species with its blue highlights). Anything else can't really hitchhike, O. Havanensis flat out couldn't survive it and lives like O. scyllarus so unlikely to be boring into rocks, P. ciliata is a spearer that mostly lives under rock and digs in sand, and Squilla Empusa/Rugosa can be found in florida but are much larger and mud/sand dependent, not really something you'd find near rock. Anything else unmentioned is probably something I've never heard of or seen personally in captivity.
Sexual color dimorphism is uncommon with most stomatopods, Gonodactylaceus is one group that males and females have unique and constant colors, males having blue tails, legs, maxilipedes, and antennal scales while females are yellow. There's more subtle ones like with G. chiragra, O. japonicus, etc.
Now I want him in a 5 gallon where I can see him every dang day! 
