/**
 * Convert a color name in NAST to a color in UI.
 * @param color One of the color names defined in `COLOR`.
 * @returns A class name with a color modifier.
 */
export declare function convertColor(color?: string): string;
/**
 * Make a block colorful.
 * @param color One of the color names defined in `COLOR`.
 * @returns A CSS class name string to add to a HTML element.
 */
export declare function colorfulBlock(color?: string): string;
/**
 * Escape special characters in a string.
 *
 * @see https://github.com/facebook/react/blob/1034e26fe5e42ba07492a736da7bdf5bf2108bc6/packages/react-dom/src/server/escapeTextForBrowser.js
 * @see https://github.com/rack/rack/issues/27
 *
 * @param str An unescaped string.
 * @returns An escaped string.
 */
export declare function escapeString(str?: string): string;
export declare function prettyTime(jsHour: number, jsMinute: number): string;
export declare function prettyDate(timestamp: number): string;
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