If your contractor has existing pools with either of these colors, you should visit those sites to see them first hand.

Generally plaster finishes will have a different cast at different depths and at different times of the day. Direct sunlight and shadows in areas will look different.

The suns shelves and shallow steps will definitely look more like a sample chip (if you were given one).

Looking at photos are a relative good example, but seeing them in "action" is best.