Tweak nord tab colors

nord-polar-night-aurora.scss

@@ -29,9 +29,9 @@ $ui-fold-arrows-color     : $ui-foreground;
 $ui-rstudio-background         : darken($ui-background, 2%);
 $ui-rstudio-color              : $ui-foreground;
 $ui-rstudio-tabs-inactive      : $nord1;
-$ui-rstudio-tabs-inactive-color: $nord4;
+$ui-rstudio-tabs-inactive-color: transparentize($ui-foreground, 0.4);
 $ui-rstudio-tabs-selected      : $nord2;
-$ui-rstudio-tabs-selected-color: $nord8;
+$ui-rstudio-tabs-selected-color: $nord5;
 $ui-rstudio-toolbar            : $ui-rstudio-tabs-selected;
 $ui-rstudio-search             : $ui-rstudio-toolbar;
 $ui-completions-background     : $ui-background;

rsthemes/nord-polar-night-aurora.rstheme

@@ -251,7 +251,7 @@ table.rstheme_tabLayoutCenter, .rstudio-themes-flat .rstudio-themes-dark-grey .g
 }
 
 table.rstheme_tabLayoutCenter .gwt-Label, .rstudio-themes-flat .rstudio-themes-dark-grey .gwt-TabLayoutPanelTabs .gwt-Label, .rstheme_multiPodUtilityTabArea .gwt-Label {
-  color: #d8dee9;
+  color: rgba(216, 222, 233, 0.6);
 }
 
 /* toolbar and selected tab */
@@ -260,7 +260,7 @@ table.rstheme_tabLayoutCenter .gwt-Label, .rstudio-themes-flat .rstudio-themes-d
 }
 
 .rstudio-themes-flat .rstudio-themes-dark-grey .gwt-TabLayoutPanelTab-selected .gwt-Label {
-  color: #88c0d0;
+  color: #e5e9f0;
 }
 
 .rstheme_toolbarWrapper {