紅海 is read as こうかい (koukai) and means Red Sea.
こうかい
koukai
べにくらげ
immortal jellyfish (Turritopsis nutricula)
こう
deep red
べにばな
safflower (Carthamus tinctorius)
べにいろ
red (color, colour)
もみじ
layered colors in garments, resembling autumn colors
こうはく
Kōhaku Uta Gassen
こうよう
leaves turning red (in autumn)
こうちゃ
black tea
こういってん
the lone woman (e.g. bright flower) in a group
こうはくうたがっせん
こうようぜんせん
autumn foliage front
こうはくじあい
contest between two groups