import numpy as np

style = [
    [0, 255, 0, 0],
    [1, 0, 255, 0]
]
def get_color(v):
    first_color = []
    second_color = []
    first_value = -1
    second_value = -1
    for s in style:
        if s[0] <= v:
            first_value = s[0]
            first_color = s[1:]
        else:
            second_value = s[0]
            second_color = s[1:]
            break
    
    if second_value == -1:
        return np.array(style[-1][1:])

    first_dis = (v - first_value) / (second_value - first_value)
    second_dis = (second_value - v) /  (second_value - first_value)
    first_color = np.array(first_color)
    second_color = np.array(second_color)
    color = first_color* first_dis + second_color * second_dis
    return color


get_color = np.frompyfunc(get_color, nin=1, nout=1)

value = np.array([0, 0.5, 0.7, 1])

print( np.stack(get_color(value)).reshape((2, 2, 3)))