import numpy as np
class ColorDtype():
    def __new__(cls):
        return np.dtype([
            ('R', np.uint8),
            ('G', np.uint8),
            ('B', np.uint8),
            ('A', np.uint8)
        ])
            
# Create a Numpy array of RGBA colors using the custom dtype
colors = np.array([(255, 0, 0, 255), (0, 255, 0, 255), (0, 0, 255, 255)], dtype=ColorDtype())
print(colors)