Secretary credits President Trump with the idea, citing black paint's ability to make the metal hotter in the sun. Homeland Security Secretary Kristi Noem announced on Tuesday that the entire border wall along the U.

Homeland Security Secretary Kristi Noem says the entire southern border wall with Mexico is being painted black to deter illegal immigration, at President Trump's request.

U.S. Homeland Security Secretary Kristi Noem said the nation's southern border walls will be painted black to better repel anyone who might try to scale them.