Instead of only changing the hue through the application of a new color of paint, modify the entire look by selecting a different finish as well. Generally, covering over one type of paint with another is a relatively easy task, particularly when you plan to cover satin paint, as this type of paint is porous enough to accept a different paint type well, making your process a simple one.
Clean the surface. If your satin paint is covered in dirt or soot, start by wiping down the walls with a trisodium phosphate solution. This solution, often referred to as TSP, will cut any grease and reduce the slipperiness of your wall. Rinse the walls with warm water after applying this solution. Give your newly cleaned walls 48 hours to dry, as you don't want to apply your new paint over moist walls.
Apply a primer if the satin paint is a darker hue than the color you are painting. Satin paint doesn't necessarily require covering with a primer; however, if you want to paint light over dark, a primer can make this transition easier. For example, if your satin paint was a bold red and you are painting with a white flat paint, priming the surface with a latex primer will allow you to cover the old paint with fewer coats.
Paint two coats of the flat paint. Apply one coat of your flat paint and allow it at least five hours to dry. Follow with a second coat, taking care to even out any paint irregularities to ensure a pristine final coat.