Paint the wall the lightest color you will be using.

Using FrogTape® Multi-Surface, run a strip of tape diagonally from one of the top corners of the wall all the way to the bottom corner of the wall. If the wall is freshly painted (just a few days or less), use FrogTape® Delicate Surface instead. My wall had cured for a week, so I used FrogTape® Multi-Surface. Also, you will want to run a strip of tape along the edges of any walls that meet up to your feature wall as shown in the image above.

From your two remaining paint colors, choose the one you want to see the most of, in my case, black, and paint that color within the triangle you just created. Immediately after your final coat, remove the FrogTape®. Let the paint cure for a minimum of 24 hours.

Using FrogTape® Delicate Surface, create another small triangle at the top of the wall.

Paint your remaining color into this triangle.

Remove the FrogTape® immediately after your last coat.