The brand will deliver paint directly to consumers' homes as well as producing a quarterly inspiration book for loyal customers.
After a four-way competitive pitch, Smoking Gun has secured an ongoing contract with the brand to be renewed annually.
The agency will deliver an integrated campaign to introduce the paint range to consumers, starting work on the account immediately.
Paint by Conran joins the agency’s growing homes and interior roster alongside clients such as Aga, Wickes and Magnet.
Sir Terence Conran said: "Colour and paint have always been a part of my life, as my father was a paint maker, so it’s wonderful to have been able to bring them together with Paint by Conran."
Smoking Gun managing director Rick Guttridge said: "Conran is a British institution, so when we were approached to launch a new concept for the company we jumped at the chance.
"This is a very exciting opportunity to launch a luxury brand with a very high quality product. We look forward to making Paint by Conran an iconic brand via a range of campaigns that will support the quality proposition."