OK, placeholders behave differently in different browsers, so you need using browser prefix in your CSS to make them identical, for example Firefox gives a transparency to placeholder by default, so need to add opacity 1 to your css, plus the color, it's not a big concern most of the times, but good to have them consistent:

*::-webkit-input-placeholder { /* WebKit browsers */
    color:    #ccc;
}
*:-moz-placeholder { /* Mozilla Firefox <18 */
    color:    #ccc;
    opacity:  1;
}
*::-moz-placeholder { /* Mozilla Firefox 19+ */
    color:    #ccc;
    opacity:  1;
}
*:-ms-input-placeholder { /* Internet Explorer 10-11 */
    color:    #ccc;
}