Experimenting with Limits

My usual approach to landscape painting is... well, to just have at it. This time around I thought it would be an interesting experiment to set some limits for myself. The first limit is actually a golden rule that I live by with all my paintings: paint with only the primary colors and use those to create the rest. The new limit I have created is the "paint inside the line" limit.. take a look, should be interesting:

Maricopa Mountains, grid limit #001