input[class="required form-control"]::-webkit-input-placeholder { /* WebKit browsers */
    color:    #C0C0C0;
}
 input[class="required form-control"]:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
   color:    #C0C0C0;
   opacity:  1;
}
 input[class="required form-control"]::-moz-placeholder { /* Mozilla Firefox 19+ */
   color:    #C0C0C0;
   opacity:  1;
}
 input[class="required form-control"]:-ms-input-placeholder { /* Internet Explorer 10+ */
   color:    #C0C0C0;
}