GMT2 bezel insert change at AD

[theken]

Yesterday I visited a local Rolex AD with an in house Rolex trained watchmaker.
I called the day before and asked if he would change the bezel insert in my GMT2. He told me on the phone that he would do it for $65 including the insert.
When I was in the store, he informed me he was not permitted to change the color of the insert (red/black to red/blue) which was the whole point of my request for the service.
Can anyone tell me if this is in fact Rolex policy or if they have had the same experience at an AD?
I have 2 GMT2s and I want to have both a coke and a pepsi version.