My jags stayed dark, almost black until they were going to spawn at about 4-5 inches. then the colors came out.
That's a male, females don't get patterning that distinct.View attachment 866005
My jag was dark for a long time maybe even like 4" then she finally got her typical coloration. i also was just growing one out for a friend and he was dark, still is, and is only around 3" or so.
Heres a pic of my female in the background.