Snapping connector lines next to each other like a "rainbow"

Hi apologies if this is an already discussed topic (just point me at the thread then please as my search didn’t bring it up!)

I can’t seem to make connection lines run neatly next to each other as identifiable different colours, i.e. running as one rainbow coloured “band” when they converge before splitting to their own boxes. A little like some of the central London tube lines on the underground map.

Can anyone please advise how I will be able to achieve this? I am trying to identify section of our supply chain’s interactions and being able to readily identify each part’s “interaction” is important.

Thanks!

PS - I am doing it on a Mac