Need help changing link colors (Kester layout)

I'm using the Kester layout and was wondering how to change the hover color of links in the header as well as throughout the website? In particular I'd like the titles underneath the thumbnails to change color from black to something else so that visitors know they are links to inner pages. (Got some feedback from a couple of friends that they had no idea they could click on the thumbnails.) I've tried some CSS codes suggested in previous posts and couldn't seem to make it work.

If it helps, here are the URLs: https://kasey.design/ https://fennel-maracas-lf7s.squarespace.com

Thanks!

Hi,

Add to Design > Custom CSS

a:hover, a:hover span {
	color: #f1f !important;
}