Key:ref:colour

ref:colour=* describes the color of the highway reference as it is found on road signs.

Disambiguation

This key is particularly prevalent in Spain, where the generally color-coded system of road number signs has many idiosyncratic exceptions. Each road is primarily known by its number, but displaying the road number sign in the wrong color would cause confusion. [1][2] For example, one does not refer to an Autovía Anaranjada (Orange Highway) but rather the number, which happens to be displayed against an orange background, unlike some of the other routes in the same network.

By contrast, in many public transit networks worldwide, as well as some small road networks, a route is associated with only a color (e.g., "Blue Route" or "Red Line"). Such colors are commonly indicated by colour=* instead of ref:colour=*.

When a route network as a whole is associated with a particular color, use network=* to indicate the network. It is generally the renderer's responsibility to display an appropriately colored graphic for each route tagged with a particular network. For recreational route networks, osmc:symbol=* also includes color information.

When a motorway's highway=motorway_junctions are color-coded, use destination:colour=* on the link ways.

Rationale

Add to the highway tagging (highway=*) the ref colour (the colour of road signs) in order to have

• more info
• better orientation
• local flavour
• administrative classification (when colours match)

Sign colour is a geographical "fact"

With this ref:colour scheme, highway tags can describe both features at the same time. We can see physical and administrative highway classification at the same time. and they can be tagged independently.

Tags

ref:colour=* way reference colour
ref:colour_tx=* way reference text colour
ref:colour_bg=* sign background colour

for international references same but with
int_ref:colour_*=*

values

black, white, blue, green, red, orange, brown, yellow, purple, grey

or hex colour number

Render

OpenMapTiles exposes ref:colour=* as an alternative to colour=* within a route's properties. [3] OpenStreetMap Americana does not yet color Spanish route shields based on this property. [4]

Render could take in account (highway=*) tags to paint the ways (as it is now),
but can also take in account ref:colour=* to paint the shields.

This way we can see physical and administrative highway classification at the same time. and they can be tagged independently

Render example

This is a road that changes physically but has same road signs

Will be in use in OsmAnd (Version > 2.??)

Tagging examples

ref:colour schema
render	highway=*	ref=*	ref:colour=*	ref:colour_tx=*	ref:colour_bg=*
International route (Europe)
E-5	highway=motorway	int_ref=E-5	int_ref:colour=green	int_ref:colour_tx=white
Spain
	highway=tertiary	ref=SO-P-6001	ref:colour=purple	ref:colour_tx=white
	highway=tertiary	ref=M-516	ref:colour=yellow	ref:colour_tx=black
	highway=secondary	ref=M-513	ref:colour=green	ref:colour_tx=white
(NW stretch from M-40 [5], blue signs. no roundabouts nor crossings)	highway=primary , motorroad=yes	ref=M-503	ref:colour=orange	ref:colour_tx=black	ref:colour_bg=blue
(SW stretch from M-40 [6], white signs. roundabouts and crossings)	highway=primary	ref=M-503	ref:colour=orange	ref:colour_tx=black
	highway=trunk	ref=N-VI	ref:colour=red	ref:colour_tx=white
	highway=trunk , motorroad=yes	ref=N-VI	ref:colour=red	ref:colour_tx=white	ref:colour_bg=blue
	highway=motorway	ref=A2	ref:colour=blue	ref:colour_tx=white	ref:colour_bg=blue