White is the lightest color but did you know that you can still color it? It's anti-climactic to say that there are only so many combinations I would consider white. But what we often think of white can also fall under warm whites and cool whites, and the temperature of the white can be established through the white point.
Think of a light bulb that you see in the store. There are warmer lightbulbs and cooler lightbulbs. (If you want to get into the details there are blackbody temperatures that determine the white point, which are measured in Kelvin. Lower Kelvin means warmer temperatures and higher Kelvin means cooler temperatures.)
Non-yellow/blue pastels could arguably be whites as well, but those would not fall under specific white point temperatures. But if you want something other than RGB white (Which this webpage uses) they're well worth considering.