Nice extra colormaps for matplotlib.

fancy_cmaps.py

class FancyCmaps:
    """
    Useful colormaps for matplotlib. Most importantly:
        - white_red
        - white_blue
        - blue_white
        - white_black
    The built-in matplotlib ones don't actually go between pure color values!!
    For ex, 'Greys' doesn't go from pure white to pure black!
    So colormaps to consider avoiding include Greys, Blues, Greens, (etc), bwr, and seismic.
    Matplotlib still has good built-in colormaps, including viridis and plasma.
    """

    @classmethod
    def white_red(cls) -> Colormap:
        """A colormap from pure white to pure red."""
        cmap = LinearSegmentedColormap.from_list('white_red', ['#ffffff', '#ff0000'])
        cmap.set_bad(color='#333333')
        return cmap

    @classmethod
    def white_blue(cls) -> Colormap:
        """A colormap from pure white to pure blue."""
        cmap = LinearSegmentedColormap.from_list('white_blue', ['#ffffff', '#0000ff'])
        cmap.set_bad(color='#333333')
        return cmap

    @classmethod
    def blue_white(cls) -> Colormap:
        """A colormap from pure white to pure blue."""
        cmap = LinearSegmentedColormap.from_list('blue_white', ['#0000ff', '#ffffff'])
        cmap.set_bad(color='#333333')
        return cmap

    @classmethod
    def white_black(cls) -> Colormap:
        """A colormap from pure white to pure black."""
        cmap = LinearSegmentedColormap.from_list('white_black', ['#ffffff', '#000000'])
        cmap.set_bad(color='#dd0000')
        return cmap

    @classmethod
    def blue_white_red(cls) -> Colormap:
        """A colormap from pure blue to pure red."""
        cmap = LinearSegmentedColormap.from_list('blue_white_red', ['#0000ff', '#ffffff', '#ff0000'])
        cmap.set_bad(color='#aaaaaa')
        return cmap