TL;DR
exploring options for pipe colours to be set - specifically in the map view.What ?
I am aware that this has been raised before (see: viewtopic.php?f=6&t=16293 from 2015), however the game has changed a fair bit since then, and there is a major gui update planned in the 0.17 release.My proposal is instead of making changes to the pipes in the standard view (like the images provided in the above 2015 link), have it as another option in the map view, similar to the power grid view.
In vanilla this could be as simple as having a single colour showing pipes with a new mod hook called something like 'pipemapcolour' for modders.
I generally play with the bob/angel set of mods which gives me ... a lot... more fluids to deal with than in the base game, and while i can zoom in and trace stuff up close, being able to see the pathways on the map in a schematic style view would be both helpful and seem consistent with the new map view options.
The only major complexity i see here is it would be preferable that the schematic/map view shows underpipes rather than gaps.
i.e. exactly like this image from the 2015 post but put it on the map not the main view:
