This idea crossed my mind some time ago, and it's just today popped back in my head.
The spark for this idea comes from trying to flick through my vehicle orders, sometimes which can be pretty long and filled with waypoints/stations, trying to find a particular station. It sometimes becomes difficult to read and leads to sometimes getting orders wrong when customizing or changing.
So I wondered... what if orders could have a custom colour chosen rather than just all black, and possibly if a 'default' can be enabled for order types (such as stations, waypoints, depot, etc).
Had a quick type in the search function, and didn't get anything up (unless I haven't used the right key words of course).
To help communicate how I was envisioning the idea in my head, I've drawn up a couple of concepts for what I feel might be an interesting and helpful little feature.
White has been preserved as 'selected order', allowing access to another bottom for selecting an individual colour. Preserved black on the station cargo/stopping position options to make it easier to identify.
Be interesting to see what people might think to such an idea, if others might find it beneficial, and of course if it is possible in the first place

All the best!