学习笔记：
green：绿色
例句：Sheep are grazing in the lush green pastures.
羊在青翠葱绿的牧场上吃草。
orange：橘色
例句：The bridge is magnificent and splendid with orange color contrasted with the green woods.
gray：灰色
例句：This monk wears a gray frock.
这个和尚穿着灰色的僧袍。
violet：紫色，紫罗兰色
例句：Roses are red, violet are blue. Glad to know friends like you.
红玫瑰，紫苣苔， 高兴认识你这样的朋友。
brown：棕色
例句：Who is wearing brown today?
今天谁穿棕色衣服?