To perform the experiment simply select a healthy brick wall with a good runup, and, lowering your head, charge. The color that flashes in bursts behind your eyes, behind the pain, just before you die, is infra-black.
It is a russian internet expression that was/is often used on the russian imageboard 2ch.ru (2chan). It means Information accuracy is 100%.
Spread to wesern world:
The expression was caught on by ultra-autistic people and stormfags spamming ron paul memes on following imageboards: northpole.fi ,4chon.org/net (not 4chan) and krautchan's /int/ back in 2009 ,2010 and 2011. On kc you would often see a picture of Comical Ali (baghdad bob) with infa 100% as a caption. If you see a non-russian using this expression then it's a balding 30+ year old permavirgin bernd which you shall bully the shit out of.