WHY ONLY WHITE FLOWERS LEFT?

 In a previous post, I wrote about devotees plucking the flowers, that were offered to the Goddess Kuan Yin, for floral baths or mandi bunga. That was in the morning.  Later in the evening when I again went to the temple, I noticed that flowers of all other colours had been plucked except white.
Earlier in the day when I was plucking the flowers with the others, I overheard one lady telling the others not to pluck the white ones as to her this colour was inauspicious.  I guess she associated it with death and bad luck.  Some Chinese also believe that flowers with thorns also shouldn't be used.
For me, I plucked flowers of all colours including white. There is no such taboo.  As for the thorny flowers, I would say that it depends on what is the purpose of the floral bath.