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.

The wall along the southern border will be painted black in an effort to make the structure too hot to climb, Department of Homeland Security Secretary Kristi Noem announced Tuesday, saying the suggestion came from President Donald Trump.