Looks like the current version of proplot does not work with matplotlib==3.6 (though it works fine with 3.5). The import: > import proplot as pplt Throws: > AttributeError: module 'matplotlib.cm' has no attribute 'cmap_d' From: proplot/colors.py:3111, > _cmap_database = _init_cmap_database() This might be fixable by changing the reference to cmap_d to point instead to matplotlib.colormaps.