Add train line colours

[danieldafoe]

GO has colours that denote each train line. Perhaps they should be incorporated.

[graypegg]

@ptrin Oops sorry! Didn't realize this was already taken care of!

[danieldafoe]

No problem at all.

I'm actually writing up a README for the project as we speak, and part of it will talk about contributing so we don't run into this issue in the future.

[danieldafoe]

@toish: Just figured I'd let you know why I haven't merged in your pull request. I was actually waiting to explore possible different ways to display the train line colours with a designer friend first before I implemented this.