If it’s still encrusting, the color definitely has time to settle in and change a bit. I think Adam’s pic looks a bit pastel due to getting blasted with light. My Pearly Cadaver is dark and hasn’t shown any coloration near the purchase photo, but it isn’t near the top and it’s still frag sized.
Some acros look amazing as frags and loose luster as they grow. Others don’t show off until they reach colony size. And some just look the same no matter the size. I’m sure you know all of this already anyhow.