[css-color-4] consistency pass on out of range clamping

Author: svgeesus

css-color-4/Overview.bs

@@ -1316,7 +1316,9 @@ HSL Colors: ''hsl()'' and ''hsla()'' functions</h2>
 	while ''100%'' is white and ''0%'' is black.
 	If the saturation or lightness are less than ''0%''
 	or greater than ''100%'',
-	they are clamped to those values before being converted to an RGB color.
+	they are clamped to those values
+	at computed value time,
+	before being converted to an sRGB color.
 
 	The final argument specifies the alpha channel of the color.
 	It's interpreted identically to the fourth argument of the ''rgb()'' function.
@@ -1852,9 +1854,11 @@ HWB Colors: ''hwb()'' function</h2>
 	as a percentage from ''0%'' (no whiteness) to ''100%'' (full whiteness).
 	Similarly, the third argument specifies the amount of black to mix in,
 	also from ''0%'' (no blackness) to ''100%'' (full blackness).
-	Values outside of these ranges make the function invalid.
+	Values outside of these ranges
+	are not invalid,
+	but are clamped to the ranges defined here at computed-value time.
 	If the sum of these two arguments is greater than 100%,
-	then at computed-value time they are normalized to add up to 100%,
+	then at computed-value time they are further normalized to add up to 100%,
 	with the same relative ratio.
 
 	The fourth argument specifies the alpha channel of the color.
@@ -2176,7 +2180,7 @@ Device-independent Colors: Lab and LCH</h2>
 	L=0% is deep black (no light at all)
 	while L=100% is a diffuse white
 
-	Values greater than 100 would correspond to specular highlights,
+	Values of L greater than 100 would correspond to specular highlights,
 	but their precise color is undefined in this specification.
 	Usefully, L=50% is mid gray, by design,
 	and equal increments in L are evenly spaced visually:
@@ -2200,6 +2204,7 @@ Device-independent Colors: Lab and LCH</h2>
 	and are close to the L axis;
 	saturated colors lie far from the L axis.
 
+
 	<!-- diagram here -->
 
 	The illuminant is D50 white, a standardized daylight spectrum with a color temperature of 5000K,
@@ -2234,10 +2239,6 @@ Device-independent Colors: Lab and LCH</h2>
 		</figcaption>
 	</figure>
 
-	In Lab and LCH, if two colors have the same L value,
-	they appear to have the same visual lightness--
-	regardless of how different their hues are.
-
 	<!-- because Luv is not widely used nowadays, no need to say LCH(ab)
 	to distinguish from LCH(uv) -->
 
@@ -2248,7 +2249,7 @@ Device-independent Colors: Lab and LCH</h2>
 	sRGB blue is lab(29.567% 68.298,-112.0294)
 	while
 	sRGB yellow is lab(97.607% -15.753 93.388).
-	In Lab, if two colors have the same measured L value,
+	In Lab and LCH, if two colors have the same measured L value,
 	they have identical visual lightness.
 	HSL and related polar RGB models were developed
 	in an attempt
@@ -2286,7 +2287,7 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 	''100%'' are permitted (for forwards compatibility with High Dynamic Range (HDR),
 	and must not be clamped.
 
-	The second and third arguments are the distances along the "a" and "b" axises
+	The second and third arguments are the distances along the "a" and "b" axes
 	in the Lab colorspace,
 	as described in the previous section.
 	These values are signed