Register color cycles packaged with ProPlot or saved to the ~/.proplot/cycles folder. This is called on import. Cycles are registered according to their filenames – for example, name.hex will be registered under the name 'name' as a ListedColormap map (see Cycle for details).

For a table of valid extensions, see ListedColormap.from_file. To visualize the registered colormaps, use show_cmaps.