I am trying to make an image in which I would like the edge of the helix to be black so that in it is more easily seen even if the image is small in publication. (For this figure I need the helix to be white and on a white background and I am losing the contrast). Is there a way to make the dumbell in a fancy helix cartoon rendition more than one color, for example white on the top and black on the thinner edge? Thanks for any advice you can give, Vanessa
