Blue paint refers to the mark given to preprocessing tokens by the C preprocessor that temporarily disables expansion of those tokens. A token is said to be painted blue when it has been disabled in this way. While the original author of the term is disputed, the 1972 C Standard  states that it came about as a reference to blue ink used by the C committee.
- PDF (94.67 KB)
- Derek M. Jones (2008). The New C Standard (Excerpted material): An Economic and Cultural Commentary (PDF).