I would like to know of a method in which if provided say 10 routes with details regarding which route intersects with which another route, we can use the least number of colours to colour the routes, without the intersecting routes having the same colour.
For example, say Route 1 intersects with Route 2,3,6,7,9.
Route 2 intersects with Route 1,3,5,7 and so on...
One can use the same colour again.
How should one go about assigning colours to each route and also minimize the number of colours used?