Hey Hulkfish,
I think your colouring is coming along nicely. It's working much better than some of your other work.
I still think you need to push it a little further and build up some stronger darks his left leg to help push it back. And in some areas like under his chin and around his face to make if pop out a little more. You might want to look at using some warm and cool colours to help push things forward and drop them back.
I think you are getting better and stronger at it, you need to push yourself a little more. Trust me I know it's tough to do I was very timid with my colour when I first got into doing colour work.
You should take a look at some of the old masters and see how they developed their work as well, art history is always a great source for reference and ideas.
Things I think you need to work with is the contrast, try and boost it a little more, the areas with most contrast will help bring objects closer while those with less will recede. Also I still think you should alter your line weight, since that's a very important part of your artwork. Again it will help create a sense of depth and volume.
But good work, keep it up.