Green overlay on image over hover

password: IICA123

https://iica-speech.squarespace.com/contact-us-v2

I am trying to get a green overlay, hex code #B3E553, when hovering over both photos (for example over the phone icon, or the background photo) 

the code I am using is this but it is doing a green overlay over one photo and white over the other, as I have two photos on top of each other

section[data-section-id="635da15a890a0774ad00dd60"] img:hover { background: green!important;
 opacity: .6;
 transition: 2s
 } 

any ideas? thanks!

Hi. I'm not sure if I understood it correctly. So you want that grey circle to not appear when you hover? Or you want the entire block to become green (also the grey circle around the icon) ?