如图所示

更改方法

打开后台-更改外观-设置外观-开发者设置-选择好需要的颜色粘贴至自定义JavaScript即可

颜色也可以自行设定，修改代码中的十六进制颜色值即可

<!--纯黑标签云-->
let tags = document.querySelectorAll("#tag_cloud-2 a");
let colorArr = ["#000000", "#000000", "#000000", "#000000", "#000000", "#000000"];
tags.forEach(tag => {
    tagsColor = colorArr[Math.floor(Math.random() * colorArr.length)];
    tag.style.backgroundColor = tagsColor;
});

<!--银白标签云-->
let tags = document.querySelectorAll("#tag_cloud-2 a");
let colorArr = ["#C0C0C0", "#C0C0C0", "#C0C0C0", "#C0C0C0", "#C0C0C0", "#C0C0C0"];
tags.forEach(tag => {
    tagsColor = colorArr[Math.floor(Math.random() * colorArr.length)];
    tag.style.backgroundColor = tagsColor;
});

<!--淡蓝标签云-->
let tags = document.querySelectorAll("#tag_cloud-2 a");
let colorArr = ["#ADD8E6", "#ADD8E6", "#ADD8E6", "#ADD8E6", "#ADD8E6", "#ADD8E6"];
tags.forEach(tag => {
    tagsColor = colorArr[Math.floor(Math.random() * colorArr.length)];
    tag.style.backgroundColor = tagsColor;
});

<!--彩色标签云-->
let tags = document.querySelectorAll("#tag_cloud-2 a");
let colorArr = ["#428BCA", "#AEDCAE", "#ECA9A7", "#DA99FF", "#FFB380", "#D9B999"];
tags.forEach(tag => {
    tagsColor = colorArr[Math.floor(Math.random() * colorArr.length)];
    tag.style.backgroundColor = tagsColor;
});

<!--天蓝标签云-->
let tags = document.querySelectorAll("#tag_cloud-2 a");
let colorArr = ["#00BFFF", "#00BFFF", "#00BFFF", "#00BFFF", "#00BFFF", "#00BFFF"];
tags.forEach(tag => {
    tagsColor = colorArr[Math.floor(Math.random() * colorArr.length)];
    tag.style.backgroundColor = tagsColor;
});

说明：如果主题中启用了pjax，还需要将上面代码添加到pjax-pjax回调函数中

部分参考来自SunPma'Blog](https://sunpma.com/532.html)