What should an IRN's tongue look like?

I've recently noticed that when my IRN stretches his tongue out to reach
something that the very back of his tongue looks blood red, almost like he's
missing part of his tongue.

Is this anything to be concerned about or is it just a normal part of their
anatomy? I haven't noticed any blood anywhere in his cage so it leads me
to believe I'm worrying about nothing but I feel the need to ask anyway.

He still seems very energetic and noisy and is eating and drinking, so
I don't really get the impression that anything is bothering him.
I first noticed it a few weeks ago but didn't really think much
about it until I noticed it again today.