/**
 * @param colorStr
 * @param out
 * @return
 */
export declare function parse(colorStr: string, rgbaArr?: number[]): number[] | undefined;
export declare function parseToFloat(colorStr: string, rgbaArr?: number[]): number[] | undefined;
/**
 * @param hsla
 * @param rgba
 * @return rgba
 */
export declare function hsla2rgba(hsla: (number | string)[], rgba?: number[]): number[];
/**
 * @param rgba
 * @return hsla
 */
export declare function rgba2hsla(rgba: number[]): number[] | undefined;
/**
 * @param color
 * @param level
 * @return
 */
export declare function lift(color: string, level: number): string | undefined;
/**
 * @param color
 * @return
 */
export declare function toHex(color: string): string | undefined;
/**
 * Map value to color. Faster than lerp methods because color is represented by rgba array.
 * @param normalizedValue A float between 0 and 1.
 * @param colors List of rgba color array
 * @param out Mapped gba color array
 * @return will be null/undefined if input illegal.
 */
export declare function fastLerp(normalizedValue: number, colors: number[][], out?: number[]): number[] | undefined;
/**
 * @param {number} normalizedValue A float between 0 and 1.
 * @param {Array.<string>} colors Color list.
 * @param {boolean=} fullOutput Default false.
 * @return {(string|Object)} Result color. If fullOutput,
 *                           return {color: ..., leftIndex: ..., rightIndex: ..., value: ...},
 */
export declare function lerp(normalizedValue: number, colors: string[]): string | undefined;
/**
 * @name clay.core.color
 * @param color
 * @param h 0 ~ 360, ignore when null.
 * @param s 0 ~ 1, ignore when null.
 * @param l 0 ~ 1, ignore when null.
 * @return Color string in rgba format.
 */
export declare function modifyHSL(color: string, h: number, s: number, l: number): string | undefined;
/**
 * @param {string} color
 * @param {number=} alpha 0 ~ 1
 * @return {string} Color string in rgba format.
 */
export declare function modifyAlpha(color: string, alpha: number): string | undefined;
/**
 * @param colorArr like [12,33,44,0.4]
 * @param type 'rgba', 'hsva', ...
 * @return Result color. (If input illegal, return undefined).
 */
export declare function stringify(colorArr: number[], type: 'rgba' | 'hsva' | 'hsla' | 'rgb'): string | undefined;