For what it&#x27;s worth, there&#x27;s a lot of 24-bit-capable terminals that aren&#x27;t MacTerm. Even xterm supports the 24-bit-color sequences, although it picks the closest entry in its 256-colour palette rather than using the 24-bit colour directly.<p>Also, you seem to be assuming &quot;xterm&quot; supports 256 colours and everything else doesn&#x27;t. The best way to figure out how many colours the terminal supports is $(tput colours). tput also looks up other useful sequences; you can &quot;tput bold&quot; to turn on bold mode, &quot;tput setaf 12&quot; to set the foreground to colour 12 (bright yellow), &quot;tput sgr0&quot; to zero all active formatting, etc.