We bought acrylic paints at Wal-mart, a dollar a bottle, black, brown, green, blue, yellow, red, and white, $7.00 total.
We mixed up a standard mushroom jar full of each of the following, using a color wheel toi match the paint to a reference photograph: Dark Gray (rock), Medium Gray (rock), Highlight Gray (rock), Damp Dirt, Dry Dirt, Dusty Roads, Drab Foliage, Peak Foliage and Dead Foliage.
We tested the colors on a small corner of the layout to see how they all worked together, made some minor changes over the course of two or three coats, and then did the whole layout using a one inch brush, and a one quarter inch brush. Dark Gray is very hard to cover with any of the foliage or dirt colors, best to use a small brush there.
We got good coverage using roughly 50% pigment and 50% water.

That brought us to a very basic level of “completion”, a place where it looks ok while running trains, as is, but allows for years of additional detailing. For grassy and bare dirt areas, we paint a small section, sprinkle on WS fine turf, and/or natural sand of varying size, not uniformly fine playground sand. The dirt road closest to the camera above is at the “basic done” stage, while the switchbacks across the valley still need some sand and paint. The grass is only about half “done” and once it’s all on, it will need some detailing to get rid of the the velvety “golf course” look.
The grass tends to take on the color of the paint used to fix it to the layout. Also, painting over areas where grass has already been applied, tends to make it clump up, unless the brush is just used to drop paint onto the grass, with no brush stroking. The best results we’ve had come from working an area and working it, allowing each treatment to dry thoroughly, until it has just the look we liked. Unfortunately, the only part that’s gotten that far along is at the f