Two Sapphire Fenix 6 Pro’s, backlight / contrast issues

I bought two fenix 6’s today, both are the Carbon grey DLC coated with sapphire glass.

Have a look at these photos, my wife's is on the left hand side and mine the right. Her looks very yellow compared to mine which looks far crisper and sharper. Both have backlight set to 50%. 

Any thoughts on if there’s a setting other than backlight that could cause this before I go back to the shop where I bought them?