GMT master ii bezel insert

[Kulayeb]

I have a GMT master ii ref 16710 with serial number starting with U66**** with black bezel insert.



I've just taken it for service at the local AD and I also requested them to change the bezel insert to coke but they refused. They said that the red/black insert was a different size and only offered the red/blue (at about 160$).

I was under the impression that all three were the same size and interchangeable. I have searched the forums here and I see people changing inserts with impunity.

Could someone shed some light why they would refuse and claim it's a different size? Is it truly different size or is it just a policy to only change to pre approved colors?

Thank you.