[css-color-4] correction noted by @vidTHEkid on twitter

Author: svgeesus

css-color-4/Overview.bs

@@ -2983,7 +2983,7 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 Converting RGB colors to Lab colors</h3>
 
 	Conversion from an RGB color space to Lab requires several steps,
-	although in practice all but the first step are linear calculations and can be combined. Taking sRGB as an example:
+	although in practice all but the first and last step are linear calculations and can be combined. Taking sRGB as an example:
 
 	<!-- make these steps links to the appropriate section in a calculations appendix -->
 	<ol>
@@ -3009,7 +3009,7 @@ Converting Lab colors to RGB colors</h3>
 	to the color space of the display.
 
 	Conversion from Lab to an RGB space also requires multiple steps,
-	and again in practice all but the last step are linear calculations and can be combined. Taking display-p3 as an example,
+	and again in practice all but the first and last step are linear calculations and can be combined. Taking display-p3 as an example,
 
 	<ol>
 		<li>Convert Lab to (D50-adapted) XYZ