Rainbow Arm
If you think this looks like a rainbow arm tattoo, we wouldn’t blame you. After all, the lines are so crisp and the colors are so incredibly vivid. You may even think that it’s some sort of filter or photoshop at work but that wouldn’t be true either.
What you’re actually looking at is the simple handiwork of physics. The OP has a prismatic window that refracts the rays of the sun to create this perfect spectrum of colors on his arm. Once again, we’re amazed at the artistic skills of nature. Who needs the rainbow filters of Instagram and Snapchat when you can have this in real life?