There are substantial challenges in building secure and safe systems on multicore processors (MCPs). Last level cache contention is undoubtedly the largest source of multicore interference, and a significant challenge for real-time systems. Here we discuss a proposed solution, called cache coloring. Opinions on cache coloring are mixed, sometimes extreme, and the implementation can be difficult and risky. This article aims to demystify cache coloring by clarifying exactly how it works. We hope that the example using a real Intel processor and accurate diagrams allows you to grasp cache coloring without getting lost in lines, sets and ways.