What is different about stain versus thinned out paint, especially with unusual colors?

A club I went to years ago had simple plywood tables (with really cool grain--wood type unknown) that had been stained so the grain was highly visible and varnished. I thought it was stunning, so I did my own surface. Using what I had kicking around, I mixed some oil paints to get a burgundy I really liked, and thinned it out alot with paint thinner. Rubbed this into the surface, quickly, and after the varnishing, it was awesome. Now I want to do a much larger area (greenish-blue), can't really find the right color (or can't trust samples too much), and besides, stains cost alot more. So, I guess I'm wondering if there's really any difference, as long as protective varnish is added.