代码如下：
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
.bg {
background-color: #6b6b83;
padding-top: 100px;
}
.wrap {
600px;
height: 100px;
position: relative;
mix-blend-mode: screen;
}
.color {
position: absolute;
600px;
height: 20px;
background: linear-gradient(to right, #aa4b6b, #6b6b83, #3b8d99);
}
.dashed {
position: absolute;
600px;
height: 20px;
background: linear-gradient(
to right,
#000000,
#000000 4px,
transparent 4px,
transparent
);
background-size: 8px 100%;
z-index: 2;
}
</style>
</head>
<body>
<div class="bg">
<div class="wrap">
<div class="color"></div>
<div class="dashed"></div>
</div>
</div>
</body>
</html>
效果如下
实现思路：利用两次颜色渐变，设置覆盖渐变的z-index，最后mix-blend-mode: screen;滤色实现