@DaLilFishie Yeah it seems pretty bold for S. fasciatus, though quite a few of the species exhibit quite a bit of red in the dorsal. Offhand I can't think of any other blennies that match particularly well.
I'm pretty sure this is S.fasciatus, this species can be rather variable and some locations are known for having a bit more of a red-dorsal population. The fact that they show it in a tank is probably because they are kept in excellent condition.
Edit: these probably came from the Indian Ocean which is known for having more red, might just be a different species that is not really known in the hobby. I can't tell for sure. For now these are sold as fasciatus. But someone should definitely look into it.
Thanks! Yes fasciatus seems like the obvious answer, but this one looked different from all the other ones I've seen so far. Still, I haven't been able to find any other species that matches, so it could very well be a fasciatus considering how variable that species is.