you can convert xy to RGB

color_wheel.py

import matplotlib.pyplot as plt
import math
def xy2color(x,y):
    norm = min(1.0,(x*x + y*y)**(1/2))
    rad = math.atan2(x,y)+math.pi
    if rad < math.pi*2/3:
        ratio = rad/(math.pi*2/3)
        r = 1.-ratio
        g = ratio
        b = 0
    elif rad < math.pi*4/3:
        ratio = (rad-math.pi*2/3)/(math.pi*2/3)
        r = 0
        g = 1. - ratio
        b = ratio
    else:
        ratio = (rad-math.pi*4/3)/(math.pi*2/3)
        r = ratio
        g = 0
        b = 1.-ratio
    return [1-min(max(r*norm,0.),1), 1-min(max(g*norm,0.),1), 1-min(max(b*norm,0.),1)]
# color campux
x = []
for i in range(100):
    x+=[(i-50)/50]*100
y = [(i-50)/50 for i in range(100)]*100
ccc = [xy2color(xx,yy) for xx,yy in zip(x,y)]
sc = plt.scatter(x,y,c=ccc)