Common CSS Infinite Animations (pulsate, opacityPulse, alertPulse, rotating).

animations.css

/* Make the element pulse (grow large and small slowly) */
/* Usage
    .myElement {
        animation: pulsate 1s ease-out;
        animation-iteration-count: infinite;
        opacity: 1; 
    }
*/
@-webkit-keyframes pulsate {
    0% {-webkit-transform: scale(0.1, 0.1); opacity: 0.0;}
    50% {opacity: 1.0;}
    100% {-webkit-transform: scale(1.2, 1.2); opacity: 0.0;}
}

/* Make the element's opacity pulse*/
/* Usage
    .myElement {
        animation: opacityPulse 1s ease-out;
        animation-iteration-count: infinite;
        opacity: 0; 
    }
*/
@-webkit-keyframes opacityPulse {
    0% {opacity: 0.0;}
    50% {opacity: 1.0;}
    100% {opacity: 0.0;}
}

/* Make the element's background pulse. I call this alertPulse because it is red. You can call it something more generic. */
/* Usage
    .myElement {
        animation: alertPulse 1s ease-out;
        animation-iteration-count: infinite;
        opacity: 1; 
    }
*/
@-webkit-keyframes alertPulse {
    0% {background-color: #9A2727; opacity: 1;}
    50% {opacity: red; opacity: 0.75; }
    100% {opacity: #9A2727; opacity: 1;}
}


/* Make the element rotate infinitely. */
/* 
Usage
    .myElement {
        animation: rotating 3s linear infinite;
    }
*/
@keyframes rotating {
  from {
    -ms-transform: rotate(0deg);
    -moz-transform: rotate(0deg);
    -webkit-transform: rotate(0deg);
    -o-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  to {
    -ms-transform: rotate(360deg);
    -moz-transform: rotate(360deg);
    -webkit-transform: rotate(360deg);
    -o-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}

This looks wrong - did you mean background-color?

50% {opacity: red; opacity: 0.75; }
100% {opacity: #9A2727; opacity: 1;}