<｜begin▁of▁sentence｜>### Instruction:
Given a custom palette defined in the matplotlib colors module, how can you determine the number of colors available in this palette?
### Response:
from matplotlib.colors import ListedColormap

# Define a custom palette
palette = ListedColormap(['#FF0000', '#00FF00', '#0000FF'])

# Get the number of colors in this palette
number_of_colors = len(palette)

print('Number of colors in the palette:', number_of_colors)
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