In reply to Misha:
> The only issue is it's confusing if the colour is the same/similar. Otherwise, half and half of any diameter is fine.
My memory is that it was rare for ropes to be so similar that they were hard to tell apart
But it was essential that both parties agreed which of the many colours in the sheath was the one that would be refered to.
This was to avoid moments along the lines of
"Watch me on yellow while I get this runner on green.."
"they've both got some yellow. When you say yellow do you mean they one that is also red and orange or the more purple one"