[css-color-4] LCH hue modulo 360. #289

Author: svgeesus

css-color-4/Overview.bs

@@ -1695,6 +1695,9 @@ Specifying Lab and LCH: the lab() and lch() functional notations</h3>
 	''90deg'' points along the positive "b" axis,
 	''180deg'' points along the negative "a" axis,
 	and ''270deg'' points along the negative "b" axis.
+	If the provided value is is negative,
+	or is greater than or equal to ''360deg'',
+	it is set to the value modulo 360.
 
 	<!-- add diagram showing hue angles in LCH for RGB primaries and secondaries in sRGB, P3, and Rec.2020 -->