As far as I know, he does not have this condition. He has what is known as centralized heterochromia. His eyes are blue/green, but have a ring of gold around the pupil, which makes his eyes seem to change 색깔 based on his surroundings. He also has a stripe of brown in his right eye, which is what 당신 are referring to. It is just a discoloration due to the heterochromia, and not coloboma.
