input,textArea的placeholder的颜色的改变

.search_input::-webkit-input-placeholder{    color:#b6b6b6;}.search_input:-moz-placeholder{    color:#b6b6b6;}.search_input::-moz-placeholder{    color:#b6b6b6;}.search_input:-ms-input-placeholder{    color:#b6b6b6;}//.search_input是标签的类名，包括（input,textArea）;