白色(bái sè) - white, the colour white in Mandarin

白色 (bái sè) is the colour white treated as a thing you can name. 白 on its own is the adjective, and 白色 is the noun you use when the colour itself is the subject, as in 我最喜欢的颜色是白色.

In front of a noun it takes 的: 白色的衬衫, 白色的车. You can often drop back to the bare 白 for short set phrases like 白纸 or 白酒, but with a plain everyday object 白色的 is the safer and more natural choice.

The trap is treating 白 and 白色 as interchangeable. 我喜欢白 sounds unfinished to a Chinese ear, the way "I like whit" would in English. When the colour is standing alone as a noun, add 色.