Fix colour selection for active tabs

css/ebi-css-build/_ebi_masthead_styles.scss

@@ -284,7 +284,7 @@
     ul li.active-trail a,
     ul li.active a:visited,
     ul li.active-trail a:visited {
-      background-color: color-pick-contrast($masthead-background, $ebi-colour-dark $ebi-colour-light, 30%);
+      background-color: color-pick-contrast($masthead-background, $ebi-colour-light $ebi-colour-dark, 30%);
       color: $masthead-background;
       border-bottom: 0;
     }

css/ebi-css-build/_ebi_theme_settings.scss

@@ -46,7 +46,7 @@ $table-font-size: 0.9rem;
 
 // masthead
 $masthead-background: $secondary-color;
-$masthead-font-color: $body-background;
+$masthead-font-color: $ebi-colour-light;
 
 // Set foundation colours
 $foundation-palette: (