Document track colours in the wiki

Map-Features had no GPX section at all, so the tracks paragraph is new
rather than an addition.

wiki/Map-Features.md

@@ -30,6 +30,16 @@ When zoomed out, nearby markers are grouped into clusters. Clicking a cluster zo
 
 When you have a day selected, a dark dashed line connects consecutive places in that day's order.
 
+## GPX tracks
+
+Tracks and routes imported from a `.gpx`, `.kml`, or `.kmz` file are drawn as lines on the map. Each track imported into a trip is given its own colour automatically, so several walks in the same area stay distinguishable without any setup.
+
+To change a track's colour, open the place and use the **Track color** row: pick one of the presets, choose your own with the colour picker, or hit the dashed cell to go back to the automatic colour — the category colour if the place has one, otherwise the default blue.
+
+Any track that carries a colour — assigned at import or picked by you — is drawn with a thin white casing so it stays readable on satellite imagery and dark basemaps. Tracks imported before this version keep their previous look until you give them a colour.
+
+Clicking a line on the map selects that track and opens its details — useful when the start markers are still clustered together. In the places list, each track shows a short stroke in the colour it is drawn in, which is how you tell which line belongs to which entry.
+
 ## Route time pills
 
 At zoom level 12 or higher, small pill-shaped labels appear between consecutive places and show the estimated **walking time** and **driving time** for each segment. Below zoom 12 they are hidden to keep the map clean.

wiki/Places-and-Search.md

@@ -63,6 +63,8 @@ The same control is available on saved places in [Collections](Collections#place
 
 Drag a `.gpx`, `.kml`, or `.kmz` file onto the Places sidebar to import all waypoints or features at once. You can also import a saved-list share URL using the **Import list** button in the sidebar header — both Google Maps and Naver Maps list URLs are supported.
 
+Imported tracks each get their own line colour so multiple routes stay apart on the map; you can override it per track from the place details. See [Map Features](Map-Features) for the details.
+
 > **Admin:** Google Maps API key is set in [User-Settings](User-Settings). Without it, OSM search is used automatically.
 
 **See also:** [Day-Plans-and-Notes](Day-Plans-and-Notes) · [Map-Features](Map-Features) · [Tags-and-Categories](Tags-and-Categories)