While the corrosion resistant properties of weathering steel allow it to be used unpainted in structural and architectural applications, it CAN be painted. However, the surface requires proper cleaning, preparation and material to achieve a painted appearance. 

Corten, or weathering steel, is a popular option for exposed steel elements. The rust forms a protective barrier and inhibits further rusting while giving the steel a rich and natural colour. Despite this property, you may want to paint it for increased longevity or for a different colour. In addition, Corten constantly exposed to water or salt spray can corrode faster than normal mild steel because the protective properties of the barrier are stripped away. Fortunately, it can be painted just like mild steel. Painted Corten has both the protection of the paint and its natural properties.