two-colour gradient

import numpy as np

def hex_to_rgb(hex_color):
    hex_color = hex_color.lstrip("#")
    return tuple(int(hex_color[i:i+2], 16) for i in (0, 2, 4))

def generate_multi_gradient_text(sentence, hex_colors):
    num_colors = len(sentence)
    color_points = np.linspace(0, num_colors - 1, len(hex_colors), dtype=int)

    r_values = np.interp(range(num_colors), color_points, [hex_to_rgb(c)[0] for c in hex_colors]).astype(int)
    g_values = np.interp(range(num_colors), color_points, [hex_to_rgb(c)[1] for c in hex_colors]).astype(int)
    b_values = np.interp(range(num_colors), color_points, [hex_to_rgb(c)[2] for c in hex_colors]).astype(int)

    return "".join(
        f"[COLOR=rgb({r},{g},{b})]{char}[/COLOR]"
        for char, r, g, b in zip(sentence, r_values, g_values, b_values)
    )

sentence = "this is a rainbow colours"
hex_colors = ["#FF0000", "#FFFF00", "#00FF00", "#00FFFF", "#8B00FF"]

colored_text = generate_multi_gradient_text(sentence, hex_colors)
print(colored_text)