/**
 * @file Color utility functions for parsing and manipulating colors.
 */
export type RGB = {
    r: number;
    g: number;
    b: number;
};
/**
 * Parse a color string (hex or rgb/rgba) into RGB components
 * @param input - Color string in hex (#RGB, #RRGGBB) or rgb/rgba format
 * @returns RGB object or null if parsing fails
 */
export declare function parseColorToRGB(input: string): RGB | null;
/**
 * Calculate relative luminance of an RGB color
 * @param rgb - RGB color components
 * @returns Relative luminance value (0-1)
 */
export declare function getRelativeLuminance(rgb: RGB): number;
/**
 * Get a readable text color (black or white) based on background color
 * Uses WCAG relative luminance formula
 * @param bg - Background color string
 * @returns "#111111" for dark text or "#ffffff" for light text, or undefined if parsing fails
 */
export declare function getReadableTextColor(bg: string | undefined): string | undefined;
/**
 * Convert RGB to rgba string with alpha
 * @param rgb - RGB color components
 * @param alpha - Alpha value (0-1)
 * @returns rgba color string
 */
export declare function rgbToRgba(rgb: RGB, alpha: number): string;
/**
 * Apply opacity to a color string
 * @param color - Color string (hex or rgb/rgba)
 * @param opacity - Opacity value (0-1)
 * @returns rgba color string, or original color if parsing fails
 */
export declare function applyOpacity(color: string, opacity: number): string;