When I walk under glass that has lava over it, the whole screen turns red until I walk out from under it. I use lava over glass to light part of my build, and this only started happening with the 14w06b snapshot.

here are pictures depicting it

http://imageshack.com/a/img208/6917/uekx.png

http://imageshack.com/a/img819/3575/vtau.png

http://imageshack.com/a/img600/2299/3t3p.png

I have also zipped a copy of my world and can upload it to a file sharing site if you need it.