紫 + Noun / 紫色 + 的 + Noun
紫 (zǐ) means "purple" and is used as an adjective to describe color. It can appear before a noun to modify it directly or be used in compound color words such as 紫色 (zǐsè). It also commonly appears in Chinese personal names.
她今天穿了一件紫色的裙子。
Tā jīntiān chuān le yī jiàn zǐsè de qúnzi.
She wore a purple dress today.
天边的云变成了紫红色,特别漂亮。
Tiānbiān de yún biànchéng le zǐhóngsè, tèbié piàoliang.
The clouds on the horizon turned purple-red; it was especially beautiful.
我最喜欢的颜色是紫的。
Wǒ zuì xǐhuān de yánsè shì zǐ de.
My favorite color is purple.