Adding mist

I wanted to experiment with adding mist to one of my already completed paintings. Below is the result with the before and after. This is a technique I'd like to work on further to help add depth or other character to certain paintings. I think if I started a painting knowing that I was going to incorporate the mist that I'd do certain things differently.

 After adding the mist. The color was titanium white with a small amount of ultramarine blue. Applied over an already dry oil painting.