Thank you both

ChickPea: nope, I haven't built it in Minecraft. I've tried to make it realistically buildable, though -- although in a real mine, you'd want to put more torches around to keep monsters from spawning in the dark.

The stations and railway would definitely work in-game: in Minecraft, you can build working machines with 'redstone', which is essentially an electrical conductor. The track has redstone-infused powered rails here and there (especially at the bottoms of slopes) to keep a minecart moving. And the stations themselves are a design I use a lot in-game, since they're pretty simple and don't take up a lot of room:
- small pit so that the track dips in a V-shape
- powered rail in the pit, which propels carts when it's powered and stops them when it's not
- redstone circuit from the powered rail to a button
- decide which direction you want the cart to go, then put it on the V so that that direction is downhill
- push the button to power the rail so that the cart unsticks and starts moving
- voila!

As for colour... here's my attempt at a limited palette, not sure how much I like it:

minecraft minetrack possible colouring.png

I tried to keep the track prominent, but I feel like it looks a bit odd. And I'm not sure whether the relative monochrome looks effective or lazy