Mehring and Robert Gates both received grants from The Woodward Foundation to travel in Europe during 1971 to broaden their art backgrounds.
Early in his career (1956–1958) he shared studio space with Thomas Downing, with whom he had been a student of Kenneth Noland at Catholic University.
Later he used some of those same forms to make "hard-edge paintings", such as Chroma Double from 1965, in the collection of the Honolulu Museum of Art.
Mehring and the other Washington Color School painters were in debt to the writings of Clement Greenberg.
In 1964 Greenberg included Mehring in his traveling museum exhibition called Post-painterly Abstraction.