I’ve heard there is but I’m not sure I remember it so I’ve texted the guy who told me.(*) In the meantime, I suggest you allocate each colour box to an instrument, as a placeholder. That way any changes that come along (or shading adjustments you make) later will cascade through.
I would also suggest you create two or three for each, so you can distinguish between acoustic/electric guitars, bass/middle/treble strings.
Worth thinking through before you start, because you probably won’t want to redo it!
(*) He says most engineers seem to use red for drums, blue for bass but beyond that he’s made up his own, so maybe the answer to your question is ‘no’. Pity if so, really, I’m a big fan of colour-coding and it would make other people’s mixers easier to follow if there were a standard.