锈 + Color Word + Noun
The verb 锈 (xiù) means 'to rust' and describes the process of oxidation that causes a reddish-brown coating on metal surfaces. It can also function as a modifier to describe the characteristic reddish-brown color associated with rust, as in 锈红色 (rust-red). This word appears in both literal descriptions of corroded metal and figurative descriptions of color.
这把刀放在外面淋了雨,已经锈了。
zhè bǎ dāo fàng zài wàimiàn lín le yǔ, yǐjīng xiù le.
This knife was left outside in the rain and has already rusted.
那辆自行车好几年没骑,链条都锈了。
nà liàng zìxíngchē hǎo jǐ nián méi qí, liàntiáo dōu xiù le.
That bicycle hasn't been ridden for years, and the chain has rusted.
铁栏杆如果不刷漆,很快就会锈。
tiě lángān rúguǒ bù shuā qī, hěn kuài jiù huì xiù.
If iron railings aren't painted, they will rust quickly.