Fixes note about 100% and 0% usage with color-mix() (w3c#6065)

Author: argyleink

css-color-5/Overview.bs

@@ -137,8 +137,8 @@ gamut mapping will occur.
 3. Colors are then <a href="../css-color-4/#interpolation">interpolated in the specified colorspace</a>.
 The result of mixing is the color at the specified percentage along the progression.
 
-Note: As a corrollary, 0% just returns the first color converted to the specified colorspace,
-100% returns the second color converted to the specified colorspace,
+Note: As a corrollary, 0% just returns the second color converted to the specified colorspace,
+100% returns the first color converted to the specified colorspace,
 and 50% produces an equal mix of both.
 
 <div class="example">