Just after designing a complex tessellated version of the famous Penrose triangle, I tried to design a simple, colored version of the same impossible object. I tried to exploit color changes with duo-colored paper, as there was a challenge on this topic that same year (2013), for the Italian origami convention. For the best result, you should find paper in three different colors, such that each sheet has two of these colors on its two faces (ie. using colors A, B, C, you should find duo-colored papers A/B, B/C, C/A). There are not many choices in commercial origami papers, but usually packs of duo kami contain a few sheets of yellow, red and green in the right combinations. Otherwise, prepare your own paper by gluing your favourite colors together!
Penrose triangle. Click on picture for diagrams.