update danger button to use global color

client/less/site/button.less

@@ -143,7 +143,7 @@ button.uk-button.dtp-button-danger {
   background: none;
   outline: none;
   border: solid 2px rgb(255, 0, 0);
-  color: #c8c8c8;
+  color: @global-color;
 
   &:hover {
     background-color: rgb(255, 0, 0);