Image rollover for 'featured image' on homepage

Hello there.

I’ve managed to make a rollover for the following page https://edessex.com/wordpress/121/

(with the aid of a plugin: https://frederik.orellana.dk/2008/03/22/image-rollovers-plugin-for-wordpress/)

however I would like the rollover to work on the homepage for the following images, https://edessex.com/wordpress

these are ‘featured images’, and as far as I’m aware I cannot do this with the plugin I’ve been using.

Any ideas would be great! Many thanks!