revert SkipLink colors to original

Author: dcastil

packages/docs/src/components/skip-link.js

@@ -7,8 +7,6 @@ export default (props) => (
     {...props}
     href="#content"
     sx={{
-      color: 'text',
-      bg: 'background',
       clip: 'rect(0 0 0 0)',
       height: 1,
       width: 1,
@@ -25,6 +23,8 @@ export default (props) => (
         left: 0,
         m: 2,
         fontWeight: 'bold',
+        color: 'black',
+        bg: 'white',
         width: 'auto',
         height: 'auto',
         clip: 'auto',