Pick a colour from a string. Repeatable but not reversable.
You can also choose a colour you would like to avoid similarity to, with a given minimum proximity.
var shc = require("string-hash-colour");
shc.convert("Hello world!") // #1b8519
shc.convert("Hello world!", { avoid: "#1b8519" }); //#b85199
shc.convert("Hello world!", { avoid: "#1b8519", proximity: 100 }); // ...still #b85199. I can't find a hash that isn't very far away immediately upon detection of proximity. But this is how you use it, anyway.
npm install string-hash-colour