I am covering up some spackling in one spot about 4 cubic inches. the spackling is considerably lighter than the white paint on the wall. i matched the paint color with a sample but i want to get the best result possible. I am going to get a flat latex paint but was wondering which would work better acrylic or vinyl latex. i want to avoid a shiny finish and i may try to dilute the paint to get a better blend. also, since i've never did much painting, i was wondering about using a self-priming paint.