/**
 * Converts a hexadecimal color string to a RGB(A) string.
 *
 * @param {string} hex - The hexadecimal color string to convert.
 * @returns {string} A string in the format `rgb(r, g, b)` or `rgba(r, g, b, a)`
 *                    representing the color.
 *
 * @example
 * hexToRgb("#FF0000") // "rgb(255, 0, 0)"
 * hexToRgb("#FF000080") // "rgba(255, 0, 0, 0.5)"
 */
export declare function hexToRgb(hex: string): string;