Hi there!
Thanks for your query.
Do you want to change the link hover color for the gallery items only?
If yes, then please use the following code in your custom CSS:
.sppb-addon-gallery .sppb-gallery li a:before{
background-image: linear-gradient(-180deg,#ff2b02 0%,#3071ff 100%) !important;
}
Note: Path towards custom CSS(Joomla 3): Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
You can use your own desired colors in the above code:)
Best Regards