how can use hsl instead of rgb for scss global declaration javascript api

that's how my next.config.js look like

// next.config.js

const env = require('./site.config').env;
const Colour = require('sass').types.Color;
const {r, g, b} = require('./site.config').customProperties;

const withBundleAnalyzer = require('@next/bundle-analyzer')({enabled: !!process.env.ANALYZE});

const config = {
  env: {
    ...env,
  },
  sassOptions: {
    functions: {
      'primaryOpacityColour()': function(){
        return new Colour(r, g,b)
        // here I want to return Colour in hsl form
      },
    },
  },
};

module.exports = withBundleAnalyzer(config);

I'm not able to return Colour in hsl form, can anyone please help me how to resolve this issue?