Factorio Forums

Something that would be really cool is being able to mark out certain zones in different colours to make your factory easier to navigate.
Another minor thing is the hitboxes: It's hard to see where you can walk through and where your machinery is in the way.

have a look under mods. I believe there is one there that you are looking for!

https://forums.factorio.com/forum/vie ... =14&t=4022

Found it - "Planning Tool Mod"