[css-color-5] Add backlinks from relative colors to the corresponding definition in CSS Color 4 w3c#13286

Author: svgeesus

css-color-5/Overview.bs

@@ -1271,6 +1271,8 @@ However, if calculations are done on missing values, ''none'' is treated as 0.
 
 <h3 id="relative-RGB">Relative sRGB Colors</h3>
 
+The meaning of sRGB colors is defined in [[css-color-4#numeric-srgb]].
+
 The grammar of the [=modern color syntax=] ''rgb()'' and ''rgba()'' functions are extended as follows:
 
 <pre class='prod'>
@@ -1338,6 +1340,8 @@ Relative sRGB color syntax is <em>only</em> applicable to the non-legacy RGB syn
 
 <h3 id="relative-HSL">Relative HSL Colors</h3>
 
+The meaning of HSL colors is defined in [[css-color-4#the-hsl-notation]].
+
 The grammar of the [=modern color syntax=] ''hsl()'' and ''hsla()'' functions is extended as follows:
 
 <pre class='prod'>
@@ -1387,6 +1391,8 @@ Relative HSL color syntax is only applicable to the non-legacy HSL syntactic for
 
 <h3 id="relative-HWB">Relative HWB Colors</h3>
 
+The meaning of HWB colors is defined in [[css-color-4#the-hwb-notation]].
+
 The grammar of the ''hwb()'' function is extended as follows:
 
 <pre class='prod'>
@@ -1418,6 +1424,8 @@ the allowed [=component keywords=] are:
 
 <h3 id="relative-Lab">Relative Lab Colors</h3>
 
+The meaning of Lab colors is defined in [[css-color-4#cie-lab]].
+
 The grammar of the ''lab()'' function is extended as follows:
 
 <pre class='prod'>
@@ -1474,6 +1482,8 @@ the allowed [=component keywords=] are:
 
 <h3 id="relative-Oklab">Relative Oklab Colors</h3>
 
+The meaning of Oklab colors is defined in [[css-color-4#ok-lab]].
+
 The grammar of the ''oklab()'' function is extended as follows:
 
 <pre class='prod'>
@@ -1505,6 +1515,8 @@ the allowed [=component keywords=] are:
 
 <h3 id="relative-LCH">Relative LCH Colors</h3>
 
+The meaning of LCH colors is defined in [[css-color-4#cie-lab]].
+
 The grammar of the ''lch()'' function is extended as follows:
 
 <pre class='prod'>
@@ -1644,6 +1656,8 @@ However, unlike HSL, manipulations are not guaranteed to be in-gamut.
 
 <h3 id="relative-OkLCh">Relative OkLCh Colors</h3>
 
+The meaning of OkLCh colors is defined in [[css-color-4#ok-lab]].
+
 The grammar of the ''oklch()'' function is extended as follows:
 
 <pre class='prod'>
@@ -1709,7 +1723,9 @@ The OkLCh chroma has dropped from 0.251 to 0.117.
 
 <h3 id="relative-alpha">Relative Alpha Colors</h3>
 
-The grammar of the ''alpha()'' function is as follows:
+Relative alpha colors refer to an origin color, and only change the alpha channel. The meaning of alpha channels is defined in [[css-color-4#alpha-syntax]].
+
+The grammar of the ''alpha()'' function, new in this level, is as follows:
 
 <pre class='prod'>
 <dfn>alpha()</dfn> = alpha([from <<color>>]