pocketmine\level\Level::setBiomeColor PHP Method

    public function setBiomeColor(int $x, int $z, int $R, int $G, int $B)
    {
        $this->getChunk($x >> 4, $z >> 4, true)->setBiomeColor($x & 0xf, $z & 0xf, $R, $G, $B);
    }