[0,1] to RGB tuple

val2color.py

import matplotlib.pyplot as plt
import numpy as np

def val2color(x):
    assert x<=1, 'x should be in the [0,1]'
    base =0.5
    if x<1/3:
        g=x*3.
        r= 1-g
        b=0
    elif x>2/3:
        r = (x-2/3)*3.
        b = 1.-r
        g=0
    else:
        b=(x-1/3)*3
        g = 1-b
        r=0
    return (r*(1-base)+base,g*(1-base)+base,b*(1-base)+base)
%matplotlib inline
x = np.linspace(0,1,100)
plt.scatter(x,x,color=[val2color(xx) for xx in x])