you just answered the round rainbow question I revised on "想過沒有? -NaCl- ♂ (33 bytes) (139 reads) 8/10/10 ". You answer is correct for normal rainbow :).
this new question is about 上彎的彩虹 and 上彎的彩虹 only.
this one is harder on earth - both rare in nature and harder to understand. 'hint' has been given by NaCl though.