色素即便是位于液泡中，它也能改变花瓣的颜色，这是因为液泡外包绕的细胞内容物是透明的，而气味分子必须穿过细胞并挥发才能为闻者所闻。

• Whereas pigments are able to alter a petal's colour even when they are inside a vacuole, because the cell contents surrounding the vacuole are transparent, smelly molecules must find a route to the sniffer's nose by getting out of the cell and evaporating.