Permission to get (only slightly) cross?

I though I would share this with you , I started it last week but due to Easter haven’t had time to do very much. My reason for putting it here is that the horse at the front will be white , I’m hoping to use the white of the paper for the majority of the horse colour. I will use some grey or grey blue for the shady bits and to show the muscles etc, I’ve never done  a painting before with so much white on a animal or anything other than snow. I don’t normally paint around the main feature but thought it might be better as I’m using white. Sorry Robert to jump in on your thread but though it might be appropriate. 

Update on the above painting , I have managed so far to avoid using white which is the reason for doing this painting. I don’t have an aversion to white paint but wanted to see if I could do it , still nor completed so time to mess it up and need the white to cover up.