change the colour of the buttons when editing avatar front end

Hi there,
I have [avatar_upload] on a page so that users can edit their avater from the front end of the website. It works great, but the buttons ‘choose image’ ‘remove image’ and ‘undo’ all have white writing.. as my background is white it’s hard to read the buttons.. is there a way for me to change the colour of the buttons or the writing in the buttons? Many thanks ??

https://www.ads-software.com/plugins/wp-user-avatar/