app/assets/stylesheets/ng-ui-tree-overrides.css.scss
.angular-ui-tree-handle {
background: #F8F8F8;
border: 1px solid #E7E7E7;
color: #777;
padding: 10px 10px;
}
.angular-ui-tree-handle:hover {
color: #333;
background: #F8F8F8;
border-color: #dce2e8;
}
.angular-ui-tree-handle {
cursor: default;
}