Other signs are red marks on the skin and lack of iron in the body.

VOA: special.2010.06.15

Mercury is a liquid metal, and mercury, the planet, is the fastest moving naked eye heavenly body. Mars, iron, why is Mars red?

水银是液态金属，水银，行星，是肉眼能看到的运动最快的天体,火星，铁，为什么火星是红色的？

麻省理工公开课 - 固态化学导论课程节选

The red color is the result of iron oxide or rust.

VOA: special.2009.04.15

But this propeller-driven aircraft is bright white with a black iron cross and the red,yellow,and black flag of the German Luftwaffe on its side.

VOA: standard.2010.07.27