Rob,
The colour could be any number of things from strain, time of year in maturing fish, habitat, sea, brackish or fresh water etc. (the camera)
The one you posted
Is less likely to be a mature winter fish as normally the pigment in the flesh migrates to the skin and gives a more intense blush of colour. On the other hand if the pigment levels are low or absent in individuals little happens. I can't quite tell from the photo if that one is a triploid but it fits the general appearance of ours.
Our strain dose through quite a few fish which are naturally the colour of the one you posted. In essence we try not to focus so much on keeping them all looking the same. In fact diversity is strength. That said, look at the spot type, volume and pattern of all three browns