Zonatus have always been one of my favorites for their bright blue tones. Yours looks like it has a lot of potential, I wouldn't really call it dull. Looks like the lighting on the tank is a bit yellowish, won't bring out the colors as much. I would bet yours improves coloration as it gets settled in the tank, and good food will help as well.
I have not kept zonatus until adulthood, but everything I have heard is that they are one of the meanest vieja, which is saying something. Good luck, post updates on progress!