I'm on a laptop, so it could just be my screen, but in all three photos, the colors just look flat. Granted, NS isn't the easiest railroad to photograph because black just isn't really vibrant. This time of the year also gives some harsh lighting. All three of those factors can make photography difficult. Luckily, we have Photoshop to help us out.
Taking the edited photo, I messed around with it to see what could be done in fixing the color since it still looked a little flat to me. I adjusted the color balance to take out a little bit of blue and add a little bit of green in the trees. I also had to really boost the saturation to make those colors pop out. A slight adjustment to the contrast and a touch of unsharp mask, and here's what I came up with.