House paints generally come in different bases. White, medium, and deep base are common. Each base has different amounts of white pigment in it and will accept different amounts of tint without affecting the quality of the paint. For instance, deep base has no white tint in it and can accept larger amounts of tint to make deep colors like black, dark brown, dark green, red, navy blue, etc. If you try to add enough red tint to a white base paint to make a rich red paint it will be so overloaded with tint that the ultimate quality of the paint will be affected, it may never cure.
To tell the truth, with the easy availability of craft water-based acrylic paints in so many different colors and for so cheap, I'd go with those.
Guy