One feature I would find useful would be to either choose the colors or at least be able to "sync" colors that have the same headings. I have two custom line graphs that use the same legend but different data and the colors are all different. Another thing, for Line and Area graphs, Yellow seriously needs to be removed. You can't read yellow text on a white background in the legend. Also, while on the color issues, I've noticed between multiple plugins, the colors are inconsistent even on the main graph & signature image graph. One of my plugins Players is blue and Servers is green, and on another they are inverted which is kinda hard to follow. Anyway, don't know if your graphing lib actually allows any of that but if it does, it would be nice.