[laumars]

That's mostly true, but there are several different methods for sending colours via escape codes and the one you discuss is just the ANSI standard. There is also 265 colour palette and even true colours (defined via RGB values). However most tools will use the standard 8 colour palette or the extended 8x3 colour palette (8 colours across 3 different intensities) because they're supported on pretty much every terminal emulator (even on Windows's cmd.exe).

So it is possible for tools to choose colours by an exact RGB value, but typically they wont.

The other thing to remember is some tools can have their colours remapped. Even tools people might not expect to be able to. eg you can configure (via environmental variables IIRC) `ls` to have specific colours for specific inode types. However in my personal opinion it is a lot of faff for very little reward.