from math import sqrt
COLORS = (
(181, 230, 99),
(23, 186, 241),
(99, 23, 153),
(231, 99, 29),
)
def closest_color(rgb):
r, g, b = rgb
color_diffs = []
for color in COLORS:
cr, cg, cb = color
color_diff = sqrt(abs(r - cr)**2 + abs(g - cg)**2 + abs(b - cb)**2)
color_diffs.append((color_diff, color))
return min(color_diffs)[1]
closest_color((12, 34, 156))
# => (99, 23, 153)
closest_color((23, 145, 234))
# => (23, 186, 241)