import type { RGBColour } from "./types";
/**
 * Converts a CSS RGB/Alpha value to its numeric equivalent
 * @param value - The value string (e.g., "50%", "127", "0.5")
 * @param isAlpha - Whether this is an alpha channel value
 * @returns The numeric value
 */
export declare function convertCssValueToNumber(value: string, isAlpha?: boolean): number;
export declare function convertCssRgbChannelValue(value?: string): number | undefined;
export declare function convertCssAlphaChannelValue(value?: string): number | undefined;
/**
 * Converts CSS RGB colour format into RGB colour object.
 * @param {string} colour - A CSS RGB colour in the format:
 *
 * - `rgb(0,0,0)`
 * - `rgba(0,0,0,0.4)`
 * - `rgb(0 0 0)`
 * - `rgba(0 0 0 / 0.4)`
 * - `rgb(50%, 25%, 100%)`
 * - `rgba(50%, 25%, 100%, 0.8)`
 * - `rgba(50%, 25%, 100%, 80%)`
 *
 * @returns {RGBColour} - RGB colour object.
 */
export declare function convertCSSRGBtoRGB(colour: string): RGBColour;