Is pink for warm or cool under tones?

It depends- these do not have much of a tint when rubbed into the skin. If you are trying to cancel out any redness perhaps go for the yellow one. I personally bought the yellow primer and it does not effect the tint or my shade at all it is pretty much translucent. I think the colours would mostly impact what sort of sheen you would get- if it leans a bit more golden or more pink. If you are cool toned the pink might look a bit nicer but in general does not matter. Hope this helps!!