acoc is an arbitrary command output colourer.
Ever wondered why the output of your favourite UNIX/Linux commands is still displayed in black-and-white after all these years?
Ever had to search back through your scroll-buffer in search of gcc errors and salient information to tell you what went wrong with your program's execution?
acoc is a regular expression based colour formatter for programs that display output on the command-line. It works as a wrapper around the target program, executing it and capturing the stdout stream. Optionally, stderr can be redirected to stdout, so that it, too, can be manipulated.
acoc then applies matching rules to patterns in the output and applies colour sets to those matches. A picture is worth a thousand words, so look at the sample screenshots in the next section.