Hello Alex,

You have a couple of options for styling the `ColumnMenu` control. I have prepared an example, which is showing the first option:

https://stackblitz.com/edit/react-mq4hbr 

In this example, we are targeting the rendering `div` and styling it with using a className and CSS. If you want to target the current element you can 'inspect' the element to see the targeted selector which you need and add the wanted styling to it.

You can also customize the KendoReact Themes to add the wanted styles. For more information about it, please check this article and our new blog post:

https://www.telerik.com/kendo-react-ui/components/styling/#toc-customizing-themes 

https://www.telerik.com/blogs/how-to-add-custom-styles-to-kendoreact-components-with-sass 

Please let me know if you need more assistance.

Regards,
Ina
Progress Telerik