EF99

I'm by no means a paint expert but I thought only pearls were 3 stage paints and metallics were 2-stage, and that was the key distinguishing thing between metallic and pearl (?).

Glacier white metallic is missing from most of the online touch up paint sources but the one I found calls it Glacier white pearl tricoat.

If GW is actually a 3 stage paint (whether it's called metallic or pearl) that makes it more difficult to touch it up without professional help.

UmIsThisThingOn

It really depends - back in my car painting days, you could do a 3 stage metallic as well as pearl and candy.

A true metallic will have the metal flake in the base coat though. I'm sure Audi only does 2 stage for production cars.

you could go to a Auto body shop and have them mix up a small amount of paint using your color code. But keeping it good for a long time would be challenging.

This is why I'm putting clear bra (and windshield) on my next Audi (S3 Sedan).

Stereodude

I thought the only difference between a pearl and a metallic paint was the size / material of the particle in the paint.