Hello, everybody, at the moment I am really lost. The problem is to create the color map that can be used in Depth_First_Search. A special feature that I have is that I want to change the Vertex color of DFS to modify the DFS. For example like this: If I make the color map global and pass it to the visitor, everything works: If the color map is not global but external, I can write the map, but it is not the same as the DFS color map and therefore I cannot manipulate the DFS algorithm: I then tried to create an internal map and work with the get() and put() functions, but I didn't succeed: I'd be so grateful if you'd give me a hint. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html