KEYWORD3 in syntax coloring

Can anyone explain what the difference is between KEYWORD2 and KEYWORD3 in keywords.txt, for syntax coloring?

I see that there are a few instances of these in the 1.0 release (for setup, loop, and a few Serialn keywords), but I can't find any documentation on it and don't understand the distinction that is being made.

The entries for the IDE display of them in preferences.txt look like:

• editor.keyword1.style=#cc6600,plain
• editor.keyword2.style=#996600,plain
• editor.keyword3.style=#993300,bold

But I don't see setup and loop appearing in that keyword3 color or in bold, in any case. It's a slightly darker brown than keyword2.

my text appears fine, I think so anyway.
Does your not look like the image I added.

Nope. Mine looks like the attached.

And, apart from whether it works or not, I'm not clear on the guiding principle for KEYWORD2 vs KEYWORD3.

have you by any chance edited your keywords.txt file
I seem to recall it is very picky about formatting

Nope. Straight out of the download...