Retaining wall - wood mockup

Thanks for these instructive photos. Is the builders foam brown when you bought it, or did you paint it? How do you sculpt it? Does just a knife work, or do you need a hot wire cutter? It looks great, and I like the way it falls away from the building. I want to make a base something like this for Swift Cottage.

Thanks! I painted the top brown to seal it before landscaping. It's purple/pink when you buy it. I cut mine with a high carbon stainless kitchen knife. The foam is somewhat resistant to cutting, but the big bad knife works well enough. Plus, the foam will be covered by landscaping materials in the end.