/**
 * Helper to parse hex and get HSV + alpha
 * @param hex Hex color string
 * @returns Object with hue, saturation, value, and alpha
 */
export declare function getColorInfo(hex: string): {
    h: number;
    s: number;
    v: number;
    a: number;
} | null;
/**
 * Helper to get custom order for greyscale values
 * @param v HSV value (brightness) from 0 to 1
 * @returns Order priority: 0 for grey/other, 1 for black, 2 for white
 */
export declare function getGreyscaleOrder(v: number): number;
/**
 * Sorts an array of hex colours by hue, then by saturation.
 * Colours with 0% saturation (greyscale) are shifted to the end.
 * Fully transparent colours (alpha = 0) are placed at the very end.
 * Accepts hex colours in #RRGGBB or #RRGGBBAA format.
 * @param hexColours Array of hex colour strings
 * @returns Sorted array of hex colour strings
 */
export declare function sortHexColours(hexColours: string[]): string[];