How to use the chroma-js.distance function in chroma-js

function findClosestColor( value, targetValues ) {
	let closestValue = value;
	let closestDistance = Infinity;
	let targetValue;

	for ( targetValue of targetValues ) {
		const distance = chroma.distance( value, targetValue );

		// This bit shortens existing variations of white to `#fff`
		if ( distance === 0 ) {
			closestValue = targetValue;
			closestDistance = distance;
			break;
		}

		// Unless white is explicitely used, let’s not convert darker colors to it
		if ( targetValue === '#fff' ) {
			continue;
		}

		if ( distance < closestDistance ) {
			closestValue = targetValue;
			closestDistance = distance;

forIn(PALETTE, (colorValue, colorName) => {
    if (colorValue === color) {
      closestColorName = colorName
      closestColorValue = colorValue
      return false
    }

    const colorDistance = chroma.distance(color, colorValue)
    if (!isNumber(closestColorDistance) || closestColorDistance > colorDistance) {
      closestColorDistance = colorDistance
      closestColorName = colorName
      closestColorValue = colorValue
    }
  })

function compareColor(a: string, b: string) {
    const a0 = chroma(a);
    const b0 = chroma(b);
    const d: number = distance(a0, b0) as any;
    return d === 0;
}

.map (function(name) {
        name.distance = chroma.distance(color, chroma(name.hex))
        return name
      })
      .sort (function(a, b) {