react-fa-picker/src/lib/utils.ts

A reusable React Icon Picker component, bundled with its own Tailwind CSS build.

import { clsx, type ClassValue } from "clsx";
import { twMerge } from "tailwind-merge";

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

// utils/color.ts
/**
 * Given a hex color like "#a1b2c3", returns true if it's light.
 */
export function isLight(hex: string): boolean {
  // strip “#”
  const c = hex.replace(/^#/, "");
  // parse r/g/b
  const num = parseInt(c, 16);
  const r = (num >> 16) & 0xff;
  const g = (num >> 8) & 0xff;
  const b = num & 0xff;
  // per ITU-R BT.601
  const brightness = (r * 299 + g * 587 + b * 114) / 1000;
  return brightness > 128;
}