1, color: red yarn is red or dark brown, Xiangyun yarn is light yellow or white.

2. Texture: Hongyun yarn is rough and the grain is not very clear, while Xiangyun yarn is delicate and the grain is clearer.

3. Usage: Hongyun yarn is usually used for national costumes, inner and outer cloaks or coats of Taoist and Buddhist Dojo, while Xiangyun yarn is mostly used for wedding red ornaments, daily scarves or silk shirts.

4. Origin: There may be different definitions in some areas. For example, in Sichuan, Hongyun yarn is considered to be a silk fabric made in Mianyang, while Xiangyun yarn is a silk fabric made in Suining.