I have some 0.7 mm lead- I cant remember the brand. I ordered it through Jet Pens...I also have Berol Turquoise leads that I use for my Staedler leadholders- much larger than the mechanical pencils. If I'm using an actual pencil, I use col-erase non photo blue pencils.
Non-photo blue pencil/leads are pretty much what I been using to draw comics with since 1999/2000.
I'll use other colors sometimes in my sketchbooks or when I'm doodling at conventions.