As I observed my Telmatochromis sp. "temporalis shell" fry today in the 5.5g grow out tank, I noticed that even at 8 weeks of age they are trying to claim space. While not much larger than a small paperclip, the fry are already defending small areas. In fact, with nearly a dozen in the tank, a couple of them have been relegated to the top of the prefilter sponge of the little AquaClear HOB I'm using.
This species, at least in my experience, begin showing signs of their adult coloration pretty early (~6 weeks). As adults, they are naturally grey to to shiny black. See my White to black post. However, like many cichlid species, their color shade can vary depending on whether they're stressed, being aggressive, being defensive, etc. My current observations lead me to believe that, even as fry that are beginning to darken, they're only dark when they aren't stressed. Otherwise, they remain a light beige to near white in color.
The Cichlid Room Companion
Tropical Fish Hobbyist
American Cichlid Assoc.
African Cichlid Hub