> Not to mention the fact that using terminfo is much easier than manually outputting the control codes.

Strong disagree. I already know many control codes by heart and can write them inside the printf strings. For terminfo, I have to include it, link against it, call bizarre functions, and then the library must be available at compile time, at runtime, and also the shared files at runtime. I have seen each one of these constraints fail for different reasons, and now I simply ignore the existence of terminfo. It is better to not abuse color, make color optional, but if you need some color you just use the xterm control codes that work everywhere.

No, don't bother with terminfo. It just gives you support for terminals that haven't been in use since the Apollo program. Nowadays it's perfectly fine to use ANSI escapes directly, which are, after all, a standard.

At the very least, use isatty() to check whether the output is actually to a terminal before polluting the log files.

isatty and checking for TERM=dumb are sensible (as well as flags to enable/disable colors). Terminfo however is a meh depencency and since common tools (e.g. git) don't bother either there is no point in anything beyond that.