refactor: update colors

Author: mrholek

scss/_bootstrap-variables.scss

@@ -25,7 +25,16 @@ $light-blue: #63c2de !default;
 
 $colors: () !default;
 $colors: map-merge((
-  "light-blue":  $light-blue
+  "light-blue":  $light-blue,
+  "gray-100": $gray-100,
+  "gray-200": $gray-200,
+  "gray-300": $gray-300,
+  "gray-400": $gray-400,
+  "gray-500": $gray-500,
+  "gray-600": $gray-600,
+  "gray-700": $gray-700,
+  "gray-800": $gray-800,
+  "gray-900": $gray-900
 ), $colors);
 
 $secondary:      $gray-300 !default;
@@ -70,8 +79,8 @@ $card-cap-bg:                     $gray-100 !default;
 // Dropdowns
 
 $dropdown-padding-y:              0 !default;
-$dropdown-border-color:           $gray-200 !default;
-$dropdown-divider-bg:             $gray-100 !default;
+$dropdown-border-color:           $gray-300 !default;
+$dropdown-divider-bg:             $gray-200 !default;
 
 // Buttons