tweak solarized

solarized-dark.scss

 $ui-rstudio-tabs-inactive       : $base02;
 $ui-rstudio-tabs-inactive-color : $base1;
 $ui-rstudio-tabs-selected       : $base01;
-$ui-rstudio-tabs-selected-color : $base2;
+$ui-rstudio-tabs-selected-color : $base3;
 $ui-rstudio-toolbar             : $ui-rstudio-tabs-selected;
+$ui-rstudio-toolbar-color       : $base2;
 $ui-rstudio-search              : $ui-rstudio-toolbar;
 $ui-completions-background      : $ui-background;
 $ui-completions-color           : $ui-foreground;
 $rlang-comment  : $base0;
 $rlang-string   : $cyan;
 $rlang-function : $blue;
-$rlang-reserved : $red;
+$rlang-reserved : $green;
 $rlang-operator : $yellow;
 $rlang-bracket  : $yellow;
 $rlang-value    : $magenta;
-$rlang-namespace: $green;
-$rlang-variable : $orange;
-$rlang-message  : $magenta;
+$rlang-namespace: $red;
+$rlang-variable : $violet;
+$rlang-message  : $orange;
 $rlang-namespace-font-style: italic;
 
 $other-tag: $rlang-variable;