Fix small UI issues with the new colortheme

www/filepicker/app-filepicker.less

@@ -3,10 +3,12 @@
 @import (once) '../../customize/src/less2/include/icon-colors.less';
 @import (once) '../../customize/src/less2/include/fileupload.less';
 @import (once) '../../customize/src/less2/include/alertify.less';
+@import (once) '../../customize/src/less2/include/tippy.less';
 
 .iconColors_main();
 .fileupload_main();
 .alertify_main();
+.tippy_main();
 
 #cp-filepicker-dialog {
     display: none;