What is the classification difference between these Russian Hazmat suits?

I haven't seen season 3 (yet), but I did capture two moments in S03E05 (towards the end) and E06 (at the very beginning):

In this second shot, it becomes more obvious that the white hazmat suits are actually grey (the two guys in the center are wearing the suits with the masks taken off):

I think the different colours could simply indicate levels of protection:

^source

Here, grey and burgundy are at the extremes on both sides, which doesn't make sense in the scene of Stranger Things, as people clad in both colours are working in the exact same environment, their suits being visually completely similar.
The only remarkable difference - apart from the colour - is that the burgundies are the only ones interacting directly with the plasma gun.
I believe therefore, that the colours must be either indicators of levels of proficiency or specialisations.

If I remember rightly, there is one colour inside while running and then when the reactor explodes the other colour comes running in. So my guess is that one colour represents "Scientists" actually working on the machine and the other is a "Recovery" team who come in to deal with any fires or...dead bodies.

the different suits don't protect from different environments but instead distinguish roles. the standard real hazmat suits are worn by the people who perform maintenance and operate the machine, thus needing a more maneuverable suit to walk around and work in. the men in red however are there to inject batteries into the firing mechanism, which requires getting extremely close to it, thus they utilize more armored and bulky suits as a safety precaution.