In addition to autumn, the chrysanthemum seems to have another peak season, because it becomes more beautiful on changing its color to purple (a poem by KI no Tsurayuki and selected in "Kokin Wakashu" [A Collection of Ancient and Modern Japanese Poetry])
秋をおきて時こそ有けれ菊の花うつろふからに色のまされば（紀貫之「古今和歌集」）