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 Nazi activity at a hot springs resort on the New Zealand coast and a gruesome murder whose solution exposes the spies. Alleyn himself is working for military intelligence in their counterespionage division; it is not until the very end of the book that one of its characters is revealed to be Inspector Alleyn in disguise. Marsh's next novel Died in the Wool also concerns Alleyn's counterespionage work in New Zealand.