postcss invalid

[caocaoio]

          plugins: [
            {
                 plugin: CracoLessPlugin,
                  options: {
                        cssLoaderOptions: {
                        modules: true,
                        url: true,
                    }     ,

            postcssLoaderOptions: {
                ident:'postcss',
                plugins: () => [
                    require("postcss-import")(),
                    require("postcss-cssnext")({
                        browsers: [
                            'last 2 Chrome versions',
                            'last 2 Edge versions',
                            'last 2 Safari versions',
                            'last 2 Firefox versions',
                        ],
                    }),
                ]
            },

            lessLoaderOptions: {
                modifyVars: {"@primary-color": "#1DA57A"},
                javascriptEnabled: true
            },
        }
    }
],

error:

./src/pages/Home/Contents/Content.less (./node_modules/react-scripts/node_modules/css-loader/dist/cjs.js??ref--6-oneOf-8-1!./node_modules/react-scripts/node_modules/postcss-loader/src??postcss!./node_modules/resolve-url-loader??ref--6-oneOf-8-3!./node_modules/craco-less/node_modules/less-loader/dist/cjs.js??ref--6-oneOf-8-4!./src/pages/Home/Contents/Content.less)

    color: #fff;
    border-bottom: 2px solid color(#00d995 blackness(40%));
                           ^

Error evaluating function color: keyword.toLowerCase is not a function