CSS Colorguard 介绍
CSS Colorguard 是一个 Node.js 扩展，用来分析CSS并标出不必要的接近的颜色值冗余
示例代码：
var colorguard = require('colorguard');
var fs = require('fs');
var css = fs.readFileSync('./file.css', 'utf8');
var output = colorguard.inspect(css, {
// 0 through 100. Lower is more similar. Anything below 3 warns you.
// 3 is the default threshold, but that's mostly personal opinion
threshold: 3,
// This color is just ignored entirely (use with caution)
ignore: ["#030303"],
// These color combinations are ignored (usually use this)
whitelist: [["#000000", "#010101"]]
});