import type { LabColour, RGBColour } from "./types";
/**
 * Indirectly converts RGB to Lab.
 * First converts RGB to XYZ, then converts XYZ to Lab.
 * @param {RGBColour} colour sRGB colour
 * @return {LabColour} Lab colour
 */
export declare function convertRGBtoLab(colour: RGBColour): LabColour;