<div class="demo">
</div>
.demo {
width: 100px;
height: 100px;
background-color: #0acb17;
}
div:hover {
animation: 1s rainbow 3 normal;
}
@keyframes rainbow {
0% {
background: #c00;
}
50% {
background: orange;
}
100% {
background: yellowgreen;
}
}