Bramble,
I can see where you're coming from regarding the case colours appearing very strong compared to other parts of the finish on that gun.
They do appear that way in those photos.
What I can say however is that it can be very hard to judge much just from photographs.
It is not difficult to photograph any rifle and make it appear good or bad, bright or dull finish, deep engraving or shallow engraving, gaps between wood and metal or no gaps anywhere, good blueing or worn blueing, all with the very same rifle, just by using different techniques with the camera and lighting.

Those colours may not look that way if you were looking at the real thing rather than those photos.