import bpy
import colorsys

rgb = bpy.data.materials["Material"].node_tree.nodes["Principled BSDF"].inputs[0].default_value
hsv = colorsys.rgb_to_hsv(rgb[0], rgb[1], rgb[2])
hue = hsv[0]

mid_point = 0.5

#if hue < mid_point:
#    hue = hue + mid_point
#    print(round(hue%1, 6))
#else:
#    hue = hue - mid_point
#    print(round(hue%1, 6))

print(round(hue%1, 6))