The ability of a paint to "hide" (cover) the existing underlying finish color is dependent on a number of factors. One factor is colorants and the other is filler. Colorants affect the viscosity of durable furniture paints, making some paints thinner than others. GF could add more filler, making Milk Paint similar to wall paint, but that would reduce the durability.

When covering existing medium-dark finishes, at least 2 coats of primer is recommended. Even with the use of a primer, additional coats of paint may be necessary.   

When covering lighter colored finishes, it may take 3+ coats of paint to achieve acceptable hide.

If you want a light color that has better coverage, consider General Finishes Chalk Style Paint.