To solve this puzzle, you'll probably need to look around in The Richmond, a few blocks along Clement & California Streets. To understand the map, you need good color vision.
This page contains spoilers from the 2-Tone Game. If you haven't already played the game, you might want to do so before continuing reading this page.
Richmond is a little walk-around puzzle.
Here's the original puzzle. In the first version, the map gave much less suggestion about where to find things. It was just a Voronoi diagram of the neighborhood.
To solve this puzzle, you'll probably need to look around in The Richmond, a few blocks along Clement & California Streets. To understand the map, you need good color vision.
The first batch of playtesters had a couple of mathematicians, who knew a Voronoi diagram when they saw it. But later playtesters stumbled. Instead of trying to figure out what point was at the "middle" of each region, they were drawn to the borders between regions. Thus, I would find myself standing with playtesters in the middle of some residential block, listening to them talk about "we need to find where the street changes from blue to pink."
So later versions of this puzzle drew circles around the places of interest, and didn't draw lines at the borders between regions.
I had to tweak the contents of this puzzle a couple of times, as there was turnover in businesses on Clement Street. There was a White Ginger Spa; that turned into a preschool with an unhelpful name. Fortunately, they'd posted a big notice saying that a new business was moving in, so I was able to fix up the puzzle ahead of time. There was a Black Sea Travel Agency; it went away a few weeks into the game. Some players let me know that they'd looked all over for something black but hadn't found it. I fixed that one up, sorry that players had run into trouble.
Some players solved this one without visiting the neighborhood, just using Google Street View. Playtester Charles Martin had lived in the neighborhood for about ten years. He kinda used Street View to solve this puzzle, except that he would call out the places of interest before Street View had finished displaying them. Click "Oh, Blue Danube!" ...and then the screen would low. Later on, I watched my parents solve this one. They didn't even need street view, my mom knew the neighborhood too well.