Gideon refer to paints in terms of their flip content. A color with high flip content, will respond, tremendously, to light. So, a white with high flip will appear to range from white, to beige, to gray, to green, to almost black depending on natural or artificial light, curves in the wall, angles, etc. Knowing which colors do that, and how they will mutate in their environment is a great way to add depth to a room.
Another secret Gideon shared with us is the idea that a neutral room doesn't have to be beige. Gideon's architecture firm designed the room above. Gideon showed us this photo to illustrate how, by using the same color palette throughout, even red could serve as a warm and calming theme for a room.