Linear colormap from one rgb color to another

cmap.py

from matplotlib.colors import LinearSegmentedColormap

def black_to_color(high_color: tuple, low_color: tuple = (0,0,0), name: str = "my_color", steps=256):
    "Get linear colormap from one rgb color to another, defaulting from black"
    
    r1,g1,b1 = low_color
    r2,g2,b2 = high_color
    
    cdict = {
        'red':    [(0.0,  r1, r1),
                   (1.0,  r2, r2)],

         'green': [(0.0,  g1, g1),
                   (1.0,  g2, g2)],

         'blue':  [(0.0,  b1, b1),
                   (1.0,  b2, b2)]}
    return LinearSegmentedColormap(name, cdict, N=steps)

blue = (0,0,1) # this is RGB for blue
cmap = black_to_color(blue)
cmap