/**
 * Copyright 2023 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
export type RGBAColor = [number, number, number, number];
export type RGBColor = [number, number, number];
export type LABColor = [number, number, number];
/**
 * Parses the given css color-value and returns it as `RGBAColor` (r/g/b in
 * range [0..255] a in range [0..1]).
 *
 * Color values are parsed using a fast-path for hex- and rgb-colors and a
 * hidden dom-element and `getComputedStyle()` to get the rgb-values for any
 * other valid css color-value including css custom-properties. Since computing
 * the color-values this way can be expensive, the values for those more complex
 * formats are cached.
 *
 * @param color
 */
export declare function parseCssColorValue(color: string): RGBAColor;
/**
 * Converts a color-value in array-format into a rgb/rgba-string.
 *
 * @param rgb
 */
export declare function rgbaToString(rgb: RGBColor | RGBAColor): string;
/**
 * Computes the relative luminance of the specified color-value (range [0..1]).
 * See http://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
 */
export declare function luminance(rgb: RGBColor | RGBAColor): number;
/**
 * Darkens the given color by the amount specified. An amount of 1 is roughly
 * one step in the material design palette.
 *
 * @param rgb
 * @param amount
 */
export declare function darken(rgb: RGBColor, amount?: number): RGBColor;
export declare function darken(rgba: RGBAColor, amount?: number): RGBAColor;
/**
 * Brightens the given color by the amount specified. An amount of 1 is roughly
 * one step in the material design palette.
 *
 * @param rgb
 * @param amount
 */
export declare function brighten(rgb: RGBColor, amount?: number): RGBColor;
export declare function brighten(rgba: RGBAColor, amount?: number): RGBAColor;