/**
 * Fetches and adjusts the color from a thumbnail image, converting it to hexadecimal format.
 *
 * @param color - The color option; if "auto", the function will fetch the dominant color from the thumbnail.
 * @param brightness - The amount to adjust the brightness by (can be positive or negative).
 * @param thumbnail - The URL of the thumbnail image to analyze.
 * @returns A promise that resolves to a string representing the hexadecimal color value (without the '#') or a default value if an error occurs.
 */
declare function colorFetch(color: string, brightness: number, thumbnail: string): Promise<string>;
export { colorFetch };