looking at Youtube- color and overlay layers

I was watching you tube today and saw a way to color images that are rendered in black and white using a color and overlay layer at low opacity- so I decided to give it a try on this quick render-it works but as stated the render layer must be filled completely so it won't color spotty.
I still needs some work on my rendering but I got a sense of form- gotta keep working... enjoy sasquatch- will make the next one a progressive...