I noticed on my shadow that the left side had a blue outline, and the right side had a red out line, and it sparked my curiosity... It reminds me of the Doppler effect, because I came to notice that the side of the shadow that's furthest from me is always the red one, and the closer side is always blue. (To show what I'm talking about, I used some random picture of a shadow I found off google to demonstrate, https://dl.dropboxusercontent.com/u/229171533/Shadow%20Question.png [Broken].) Later, I noticed it's also with objects as well, and their outline too! So yeah, the point of this thread is, what's causing this?