That's not the terminal but rather the Compile tab. The built-in terminal does support ANSI escape sequences. I think there was a pull request or at least some discussion on the mailing list about having the Compile tab parse ANSI escape sequences, but I don't remember what happened about it.

--- Reply to this email directly or view it on GitHub: https://github.com/geany/geany/issues/669#issuecomment-143498633

Lines in the compiler tab are coloured to indicate those that Geany has parsed as containing a reference to a file location where the error occurs. So the colour therefore indicates you can click on them to go to that location.

Using some other colour would remove that indication.

--- Reply to this email directly or view it on GitHub: https://github.com/geany/geany/issues/669#issuecomment-143505900