How can I alter the 'add to cart' button color in the refresh theme?

[LUMEO]

Hello. I would like to know how to change the color of the "add to cart" button in the refresh theme without changing the colors of other buttons. The best thing to do is for someone to send me the code, which I then have to paste into base.css. Here's a screenshot from the button I'd like to Change https://prnt.sc/oIu2OwBpItX5