Thanks for the proposition, John, but that's not really necessary. Remember BASIC is in fact only one third of FBSL's net worth. I don't think any stock highlighter (except for FBSL's official Eclecta editor, of course) would be able to highlight FBSL's composite scripts adequately.
As far as example code snippets are concerned, stock C and Intel asm highlighters will suffice, and any decent contemporary BASIC highlighter like VB, or PB, or O2, or SB for that matter, will do just fine. FBSL doesn't utilize any 20th century legacy esoterics.