These textures are a lot of fun. Here is a choropleth using a few predefined textures on some random data.
Modified http://riccardoscalco.github.io/textures/textures.min.js to a secure url
https://d3js.org/d3.v3.min.js
https://d3js.org/topojson.v1.min.js
https://riccardoscalco.github.io/textures/textures.min.js