I've long known about a paint variant on Lumat's quiver, where either just the arrow heads, or both the heads and the shafts are painted. It's not the most exciting variant in the world, and it wasn't especially high on my target list of figures to acquire as a consequence, however I recently bit the bullet and bought one. It arrived today, and to my delight I realised that the hood and quiver were also a noticeably different shade of grey to the one which has been sitting in my main collection for years. And that got me thinking, because I have a few doubles of some figures that have been in storage for quite some time, and they went into storage before I became quite so interested in variants. And so I dug it out today, knowing that the quiver paint was the same as on my main collection figure, but curious to know if anything else was different about it, and... bingo! It had a third shade of grey on its hood!
I'm not sure if any of these differences is down to discolouration. I do know that the Lumats with the painted arrow shafts are generally more prone to having their torsos yellow, so I suppose it's perfectly possible that the hoods might discolour as well, even though they are a very different kind of plastic, so I will post a question in the main Vintage Collecting Chat section to see if any members can definitively answer the question.
However, in the meantime here are my now THREE Lumat variants :-D. It's not just the hoods and quivers that differ, you will notice that the nose and lip paint also varies from light grey to mid grey to a darker blue grey: