woof, in my experience - which is on large, exterior surfaces - the perception of the colour depth itself isn't affected one bit by whether the paint is satin or matt, and I believe the same is true for interiors.
The finish affects perception on the surface it's painted on to - so if you have a poor surface, matt disguises it, satin draws the eye to any imperfection.
Brightness or softness is down to the ambient light conditions, so if satin's what you want, use that.