find-color-with-csstree.js

const csstree = require("css-tree");
const cssDefinitions = ["color"];
const ast = csstree.parse(`
.some-selector {
  color: black;
  border: 1px solid #fff;
}
`, { parseValue: false });

csstree.walk(ast, {
  visit: 'Declaration',
  enter: function(decl) {
    const ast = csstree.parse(decl.value.value, {
      context: "value"
    });

    const fragments = csstree.lexer.findValueFragments(decl.property, ast, 'Type', cssDefinitions[0]);
    if (fragments.length) {
      console.log(`${decl.property}: ${decl.value.value}`);
      fragments.forEach(f => {
        const color = f.nodes.first(); // color node
        console.log(csstree.generate(color))
      });
      console.log('');
    }
}});