/**
 * Finds the nearest hexadecimal colour in a palette to the given hex colour.
 *
 * @param {string} colour - The hexadecimal colour to find the nearest match for.
 * @param {string[]} palette - An array of hexadecimal colours to search for the nearest match in.
 * @returns {string} The hexadecimal colour in the palette that is closest to the given colour.
 * If the palette has fewer than 2 colours, or if it is undefined or null, the original colour is returned.
 */
export declare function findNearestHexColour(colour: string, palette: string[]): string;