I have painted a lot of rooms red and yes, it is a difficult thing to get a good quality paint where they actually have taken the time to ground their pigments correctly. Don't want to cause a ruckus, but my worse experience was with RL. Depending on your budget and how much room you have to cover, I generally turn to art stores because the grade of paint artists use tends to be much higher than the paints we use to paint our walls. I have recently discovered a swiss brand called Lascaux that is made for interior and exterior painting (I guess it is a popular brand for muralists) and I have been using it in a lot of my professional work. They have a line called Studio that is perfect for painting rooms plain colors. All synthetic pigments, finely ground and manufactured to create one of the most consistent covering paints I have ever used. The problem is finding it, generally you have to try an art store or catalog such as Jerry's or Artist and Craftsman.