fix stupid typo

Author: svgeesus

css-color-4/Overview.bs

@@ -1940,7 +1940,7 @@ Predefined colorspaces: ''srgb'', ''image-p3'', ''a98rgb'', ''prophotorgb'' and
 				<tr><th>Red chromaticity</th><td>0.640</td><td>0.330</td></tr>
 				<tr><th>Green chromaticity</th><td>0.300</td><td>0.600</td></tr>
 				<tr><th>Blue chromaticity</th><td>0.150</td><td>0.060</td></tr>
-				<tr><th>White chromaticity</th><td>0.3127</td><td>3290</td></tr>
+				<tr><th>White chromaticity</th><td>0.3127</td><td>0.3290</td></tr>
 				<tr><th>Transfer function</th><td colspan="2">see below</td></tr>
 				<tr><th>White luminance</th><td colspan="2">80.0 cd/m<sup>2</sup></td></tr>
 				<tr><th>Black luminance</th><td colspan="2">0.80 cd/m<sup>2</sup></td></tr>