I'm using OmniGraffle Pro to build a fishbone type decomposition using the included "Lines" diagram style. I want to change the green of the third level to be more of a forest green. I went in and changed the color for each line and text element, but then when I add to the outline, it reverts back to the lime green for new outline elements. How do I change the style so that when I add stuff it will follow my new style choices rather than what's programmed into it for the "Lines" diagram style?