2.0 block colors in Scratch 3.0. Made by infinitytec, released under the MIT License.
Use Tampermonkey (get it at https://tampermonkey.net/) or a similar browser extension, then click this link and install: https://github.com/infinitytec/2.0-Colors/raw/master/2Colors.user.js
Right now I recommend having this script installed seperately, as it is undergoing a lot of change. If you want to make this be part of your userscript, feel free to do so. I may make a CSS-only version just so that the latest version can be included immediately, but I want to see it finished first.