If there are 100 blue eyed people, each of them will kill themselves on day 99 (because they can only see 99 other blue-eyed people). However, the brown eyed people will wait until day 100.
On day 100, a brown eyed person won't know that he is brown eyed, only that he is not blue eyed, so he could have green eyes, purple eyes, etc.
On day 100, a brown eyed person won't know that he is brown eyed, only that he is not blue eyed, so he could have green eyes, purple eyes, etc.