@danielkalen/simplybind/benchmarks/src/bower_components/aurelia-binding/doc/example/binding-value-converters/bi-directional-value-converters/rgb-to-hex.js

Magically simple, framework-less one-way/two-way data binding for frontend/backend in ~5kb.

export class RgbToHexValueConverter {
  toView(rgb) {
    return "#" + (
      (1 << 24) + (rgb.r << 16) + (rgb.g << 8) + rgb.b
    ).toString(16).slice(1);
  }

  fromView(hex) {
    let exp = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i,
        result = exp.exec(hex);
    return {
      r: parseInt(result[1], 16),
      g: parseInt(result[2], 16),
      b: parseInt(result[3], 16)
    };
  }
}