Most paints have a reflectivity percentage listed. I was surprised to find that other colors can reflect more light than white. I used a Behr paint call Havana Cream. It is a pale yellow that really reflects light! My MIL was a "die hard" stark white fan until she saw my walls. Even my hubby, who hates yellow, loves the color. It is soft and soothing and makes the room seem as if it it filled with sunshine!
I'm sure other pale colors will reflect as much, or more than white. Just ask the "paint guy or gal" at the store.