html5默认提示文字placeholder更改颜色

/* placeholder颜色 */
input::-webkit-input-placeholder, textarea::-webkit-input-placeholder { color: #dbdbdb;}
input:-moz-placeholder, textarea:-moz-placeholder { color: #dbdbdb;}
input::-moz-placeholder, textarea::-moz-placeholder { color: #dbdbdb;}
input:-ms-input-placeholder, textarea:-ms-input-placeholder { color: #dbdbdb;}