Colour Scheme is a detective novel by Ngaio Marsh; it is the twelfth novel to feature Roderick Alleyn, and was first published in 1943. The novel takes place in New Zealand during World War II; the plot involves suspected espionage activity at a hot springs resort on the coast of New Zealand's Northland region and a gruesome murder whose solution exposes the spy. Alleyn himself is working for military intelligence in their counterespionage division. Marsh's next novel Died in the Wool also concerns Alleyn's counterespionage work in New Zealand.