修改默认字体颜色(style):
input::placeholder{
color: green;
}
<input type="search" name="se" placeholder="默认值 输入内容则不显示" autofocus="autofocus">
<input type="search" name="se" placeholder="默认值 输入内容则不显示" autofocus="autofocus" autocomplete="off"> <br />选择多个文件:<br /> <input type="file" multiple="multiple"> <br />