Why is Razib Green?
Because he's in the Matrix.
Seriously, though? Because his camera isn't great, and the lighting may not be the best. Sometimes fluorescent lighting gives a greenish tinge to digital photographs, because of differences in the way cameras and eyes work.
Link.
"Razib Khan has an academic background in the biological sciences, and has worked for many years in software. He is an Unz Foundation Junior Fellow. He lives in the western United States."
Razib's writings can be found on his blog, Gene Expression.