/**
 * Converts RGB values to a hexadecimal color string.
 *
 * @param {number} r - The red component of the color (0-255).
 * @param {number} g - The green component of the color (0-255).
 * @param {number} b - The blue component of the color (0-255).
 * @returns {string} A string in the format `#RRGGBB` representing the color.
 */
export declare function rgbToHex(r: number, g: number, b: number): string;