Allow colouring paths

marker.nix

@@ -98,11 +98,12 @@ in
         };
 
         arrival = {
-          location = "Prague";
+          location = "Chile";
         };
 
         pathStyle = {
           weight = 10;
+          color = "purple";
         };
       };
 

path.nix

@@ -19,8 +19,29 @@ let
         type = lib.types.ints.between 1 20;
         default = 5;
       };
+
+      color = lib.mkOption {
+        type = colorType;
+        default = "blue";
+      };
     };
   };
+
+  colorType = lib.types.either
+    (lib.types.strMatching "0x[0-9A-F]{3}([0-9A-F]([0-9A-F]{2}([0-9A-F]{2})?)?)?")
+    (
+      lib.types.enum [
+        "black"
+        "blue"
+        "brown"
+        "gray"
+        "green"
+        "orange"
+        "purple"
+        "red"
+        "white"
+        "yellow"
+      ]);
 in
 {
   options = {
@@ -64,6 +85,7 @@ in
               attributes =
                 [
                   "weight:${toString path.style.weight}"
+                  "color:${path.style.color}"
                 ]
                 ++ builtins.map attrForLocation path.locations;
             in