Assuming that the mahogany floors that are mentioned are simply clear coated or lightly stained, the color of the floor will be a reddish-brown. Lighter and more neutral colors will accent the mahogany nicely. The size and purpose of the room will influence the decision as well.
I think the best paint colors to go with mahogany floors are dark red (not maroon but, not fire engine red eithet), green (not evergreen or pastel green), and any kind of yellow will match well.
Consider the furnishings and art work in the room. Use your favorite items as a guide to what paint colors would be pleasing on the scales of warm/cool, and light/dark.
For a warm room, try caramel colors. For a room that is vibrant, strong primary colors would work very well. In the end, choose a color that pleases you.
It depends on the size of the room. If you have a smaller room with dark mahogany floors, you would want to go with a lighter color. A lighter shade of green might compliment nicely.