pix_color = (180, 100, 50)
cmy_adjust = (40, -60, 10)

ref = ({
    # reds
    'range': 180-100,
    'values': (
        (204, 149, 114),
        (204, 149, 114),
        (204, 149, 112),
        (204, 149, 104),
        (204, 149,  95),
        (204, 149,  86),
        (193, 149,  77),
        (182, 149,  69),
        (170, 149,  60),
        (159, 149,  51),
        (148, 148,  42),
        (137, 145,  34),
        (126, 142,  34),
        (124, 138,  34),
        (124, 135,  34),
        (124, 132,  34),
        (124, 129,  34),
        (124, 126,  34),
        (124, 122,  34),
        (124, 119,  34),
        (124, 116,  34),
    )
},{
    # neutrals
    'range': (255*2-(abs((180*2)-255)+abs((50*2)-255))+1)/2,
    'values': (
        (217, 176, 150),
        (217, 176, 150),
        (217, 176, 148),
        (217, 176, 134),
        (217, 176, 120),
        (217, 176, 106),
        (200, 176,  93),
        (182, 176,  79),
        (165, 176,  65),
        (148, 176,  51),
        (130, 175,  37),
        (112, 170,  25),
        ( 95, 165,  25),
        ( 92, 160,  25),
        ( 92, 155,  25),
        ( 92, 150,  25),
        ( 92, 145,  25),
        ( 92, 140,  25),
        ( 92, 135,  25),
        ( 92, 130,  25),
        ( 92, 125,  25),
    )
})

def clip(v, min_v, max_v):
    if v < min_v: return min_v
    if v > max_v: return max_v
    return v

def comp_adjust(adjust_range, value, adjust, k):

    # FIXME: how to use k? :(
    adjust += k # XXX: incomplete/wrong

    left_pcent  =      value/255.
    right_pcent = 1. - value/255.
    return round(clip(-adjust, -left_pcent, right_pcent) * adjust_range)

for x in ref:

    adjust_range = x['range']
    k = -100
    for values in x['values']:

        res = [comp_adjust(adjust_range, pix_color[i], cmy_adjust[i] / 100., k / 100.) for i in range(3)]

        ar, ag, ab = res

        rr, rg, rb = [values[i] - pix_color[i] for i in range(3)]
        print 'K %4d: RES{%4d %4d %4d} REF{%4d %4d %4d} ERR{%4d %4d %4d}' % (k, ar, ag, ab, rr, rg, rb, ar-rr, ag-rg, ab-rb)
        k += 10
    print '---'