[cssom-1] correct linking to <<color>>

Author: svgeesus

cssom-1/Overview.bs

@@ -109,7 +109,7 @@ urlPrefix: https://fetch.spec.whatwg.org/#concept-
 
 <pre class='link-defaults'>
 spec:css-display-3; type:value; for:display; text:table
-spec:css-color-4; type:property; text:color
+spec:css-color-4; type:value; text:color
 spec:css-position-3; type:property; text:left
 spec:html; type:element; text:style
 spec:css-namespaces-3; type:dfn; text:namespace prefix