Catch is designed to "just work" as much as possible. For most people the only configuration needed is telling Catch which source file should host all the implementation code (CATCH_CONFIG_MAIN).
Nonetheless there are still some occasions where finer control is needed. For these occasions Catch exposes a small set of macros for configuring how it is built.
Yes, I am English, so I will continue to spell "colour" with a 'u'.
When sending output to the terminal, if it detects that it can, Catch will use colourised text. On Windows the Win32 API, SetConsoleTextAttribute, is used. On POSIX systems ANSI colour escape codes are inserted into the stream.
For finer control you can define one of the following identifiers (these are mutually exclusive - but that is not checked so may behave unexpectedly if you mix them):
CATCH_CONFIG_COLOUR_NONE // completely disables all text colouring CATCH_CONFIG_COLOUR_WINDOWS // forces the Win32 console API to be used CATCH_CONFIG_COLOUR_ANSI // forces ANSI colour codes to be used
Note that when ANSI colour codes are used "unistd.h" must be includable - along with a definition of isatty()
Typically you should place the #define before #including "catch.hpp" in your main source file - but if you prefer you can define it for your whole project by whatever your IDE or build system provides for you to do so.