I was just looking at the felt AR1 frameset, with an eye towards a Red build.
The AR1 complete lists a DA hollowtechII bb
The AR1 frame set actually doesn't state what BB are compatible.

So would this work with a red bb30? How would I know?

No it won't work with a BB30 bottom bracket.

gxp?

You would know because the Dura Ace Hollowtech II isn't a BB30 bottom bracket. It's a threaded bottom bracket (or pressed, in certain cases of the BB86 or BB90 stuff, but still the same bracket).

It's probably 68mm English threaded, but their website sucks, so I can't tell you.

I have seen AR1 built up with Red elsewhere in the internetz. How would it be done?

BB30 is an option for the Red crankset, it also comes with a GXP BB.
https://www.sram.com/sram/road/produc...m-red-crankset

Red is available in a standard threaded BB or BB30. You can buy English or Italian threaded GXP external bearings.

To beat this to death - BB30 is just a specific BB standard. In order to run a BB30 you have to have a frame that was built to use one. You'd know. This one is not. HollowtechII is Shimano's outboard bearing cup standard designed to be used on standard threaded BB's. <> BB30. Red cranks - as umd pointed out - are available in both BB30 and Regular threaded BB standard. SRAM's name for their regular threadded BB is Truvativ's "GXP"

If you don't have a BB30 frame - then you can't run BB30.

So are you saying that to use SRAM cranks I'd need a GXP bb, and that the GXP would be compatible with this frame?

Yes

Here is more than you need to know about installing it (scroll down to SRAM):

https://www.parktool.com/repair/readhowto.asp?id=95

But basically, the 2 bearing cups just screw in like large bolts using the BBT-19 socket, and then the 2 sides of the crank go on and the left side crank bolt clamps the whole thing together.

Alright, thanks for clearing that up. I have no preference between BB30 and GXP, i just wanted to know if Red was doable. But I understand it now.