The grey is usually suggested as a light neutral color. ANY soft color grout can be used and still get the same effect.

I wouldn't mix the beige with the grey. You need to decide on one or the other for both. Think about the overall look you want for the room. Grey will definately be cooler and beige will be warmer. Grey will work with the crema and beige will probably work with the subways, you just have to decide which you like best.

Thanks for the input. I was thinking I should stick with only one color grout, but started second guessing myself. I am just hoping that the "neutral beige" doesn't look dirty. The bathroom is intended to be white/beige overall with a blue walls so throwing in the grey doesn't seem to make sense.

Have you got time to do a mock up? Glue a few subway tiles to a board and mix up a little of the beige grout. Smear it on, wipe away the excess, let it dry. Then you'll know for sure before your whole bathroom is done in it.

budge 1 - Great idea! I'll ask the contractor to get me some tiles and grout. I'm guessing they won't be able to start tiling until later in the week. Maybe he'll even do the mock up for me - think he'd be afraid I'd slow down the process if he had to wait for me.