The issue with CSS hover image not functioning in Firefox, although it works fine on Chrome.
Here are the snippets of code that I am using for this:
.col-md-2 .angelhack {
height: 65px;
width: 188px;
content: url(../img2/logo_angelhack.png);
}
.col-md-2 .angelhack:hover {
height: 65px;
width: 188px;
content: url(../img2/logo_angelhack_colored.png);
}