Metal Gear Solid 3 HD: Didn't get Fire camo?
Solution 1:
After defeating The Fury, the fire camo will be in Groznyj Grad Underground Tunnel:
Source: http://www.darthscreencapture.com/MGS3/u.html
Solution 2:
I had this problem myself and ended up reloading to find it. It's directly to your left after the cutscene.