title: matplotlib: single colored colormap with saturation
body: <p>How can I create a linear colormap, where the saturation goes from 0 to 1 for a single custom RGB color?</p>
  
  <p>I need a map like the 'Blues' or 'Greens' (see here: <a href="http://www.scipy.org/Cookbook/Matplotlib/Show_colormaps" rel="noreferrer">http://www.scipy.org/Cookbook/Matplotlib/Show_colormaps</a>) but for a custom color.</p>
  
  <p>I think it may be achievable with LinearSegmentedColormap, but I don't understand how I need to set the parameters.</p>