It is an off-white with beige undertone and should not look stark white. It could be the natural light. Try it on another side of the house. It's rare a paint is mixed incorrectly, as it is computerized.

compared to what?

Have you painted it on yet?

It will dry darker, but in the bright light of daylight it will look white.

Did you test it first? It will definitely look lighter on the exterior. For example, we’ve used Ben Moore Swiss Coffee on the exterior and it looked very white. Yes, they’re different but both are considered off white.