Generate unique(ish) colors for city names using Dopplr's algorithm.
In 2007, the team at Dopplr posted about their technique for generating colors for cities (linked to the Wayback Machine, because the Internet is cruel).
Here's the relevant bit:
We wanted a deterministic RGB colour value for each city [...] we take the MD5 digest of the city’s name, convert it to hex and take the first 6 characters as a CSS RGB value.
This is that, basically.
npm install blueshift
var blueshift = require("blueshift");
blueshift("San Francisco");
// -> '#f4334f'