I have created some custom skins but need to add a different image per skin. I have added the property (like below) to each of my custom skins but it doesn't seem to work.

"skin-client-logo": "/images/someclientname_logo.jpg"

This it's used like this:-

 <div class="logo-wrapper waves-light waves-effect waves-light skin-client-logo"></div>

However, this doesn't seem to work.