void ColorChange(Color color = *Color.black*)
{}
์ด์ผ€ ํ•˜๊ณ ์‹ถ์€๋ฐ Color.black์ด ์•ˆ๋“ค์–ด๊ฐ€์ง๊ธฐ๋ณธ๋งค๊ฐœ๋ณ€์ˆ˜๊ฐ’์€ ์ปดํŒŒ์ผํƒ€์ž„ ์ƒ์ˆ˜์—ฌ์•ผํ•œ๋Œ€