I've read and been told that hover effects (something simple like background color change on a button) are now supported by gmail. I haven't been able to make any hover effect work in gmail - anyone had success?

<style>
.txt-color:hover {
        color: #c81c16 !important;
    }
</style>
<A HREF="#" style="color:#43b9d3; text-decoration:none;"><SPAN style="font-size: 18px; line-height: 30px;" class="txt-color">
Change Color</SPAN></A>