.anim-grey-to-blue-1 {
    -webkit-animation: color-change 5s infinite;
    -moz-animation: color-change 5s infinite;
    -o-animation: color-change 5s infinite;
    -ms-animation: color-change 5s infinite;
    animation: color-change 5s infinite;
}

@-webkit-keyframes color-change {
    0% { color: #DDD; }
    50% { color: #515151; }
    100% { color: #DDD; }
}
@-moz-keyframes color-change {
    0% { color: #DDD; }
    50% { color: #515151; }
    100% { color: #DDD; }
}
@-o-keyframes color-change {
    0% { color: #DDD; }
    50% { color: #515151; }
    100% { color: #DDD; }
}
@keyframes color-change {
    0% { color: #DDD; }
    50% { color: #515151; }
    100% { color: #DDD; }
}