Allows user to select colors from arbitrary named colormaps and color cycles.
For a smooth colormap, usage is e.g.
color=('Blues', 0.8). The number is the colormap index, and must be between 0 and 1.
For a color cycle, usage is e.g.
color=('colorblind', 2). The number is the list index.
These examples work with any matplotlib command that accepts a