Where did you find this info and why did you put I guess? 🙂
There's various sites that can offer information about Apple devices, when you supply the serial number.
https://www.imei.info/apple-sn-check/?sn=6U5450UYSZB
That site also reports that the original color, as shipped by Apple, was white.
IMHO, the painter, if they wanted to do a decent job, would have removed the screen, so the case edges could also be colored. Whoever it was, decided not to do that, so the screen edges there remain the original white.
And, again, I suspect that National Geographic Channel must have sold that originally (why else would it be engraved with that?), or it was a special promotion of some kind, involving NGChannel.
And, it appears to be that company's logo - another indication that NGC did that, not Apple.
It's hard to say if it was red from NGC, or someone else painted it later - again, not finished as nicely as a commercial service that might do that, like Colorware. (maybe just wear and tear after nearly 15 years... )
Your iPod color looks like the Ferrari red that Colorware did with that nano -
http://www.gearlive.com/news/article/colorware_ipod_nano_09180328