What colour are they?这么说对吗?能不能说What colours are they?

问题描述:

What colour are they?这么说对吗?能不能说What colours are they?
什么时候用What colours are they?

不行.
colour是不可数名词,不能加s.What colours are they?这么说是错的.还是用What colour are they?好.