Some feedback on OP article:
Is that really the name of these? Memory Alpha refers to them as simply "engineering suits
The Rad Suit was a completely new concept that had no counterpart in TOS.
That's false. There were hazard suits seen in TOS
everything you ever wanted to know
No. There's no mention of the red collars
used on the suits in The Wrath of Khan,
which I assumed were for the cadets.
Also, there's no mention that Lieutenant Cleary
wore the black collar of the "rad suit" with his gray jumpsuit uniform.
There's no bibliography, and so no way to authenticate what's said, without the readers digging on their own, so that's hardly helpful. Generally speaking, I don't bother with pages that claim to report a lot of facts, but don't have bibliographies. There're also no credits and no acknowledgements of copyrights on the photos and no appropriate claims of fair use.