The formula generator helps you build color coded lists or calendars in SharePoint.
To build your color coded field:
1/ Fill out the form.
2/ Click on "Generate formula" and copy the formula.
3/ Create a calculated column in your list, where you'll paste the formula.
4/ Get the script available under the download tab and add it to the page, under your list.
See this article for detailed explanations (and this other one for calendar views).