<span class="pattern left">
<img src="../static/image/download_pattern_left.png" data-cfsrc="../static/image/download_pattern_left.png"/></span>
css
/* 使2个背景图变灰色*/
.pattern{
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter:grayscale(100%);
-o-filter: grayscale(100%);
filter: grayscale(100%);
filter:gray;
}