It was a slightly embarrassing victory. One big battle, mostly Japanese suicide, a lot of people injured in accidents, and in the second, bigger landing — the Japanese had already left, the casualties were all self inflicted.
Which makes it hard to search for. I don’t think that the 93rd was “unskilled”, but they may have been used for that, or there may have been less skilled units that I haven’t even heard of yet. I would have thought that the fact the guy was wearing a combat helmet indicated Combat Engineers, but I haven’t seen a reference to a black Combat Engineer group at Attu Island – but could that be because they were “invisible”?
I find very few pictures that are labeled “unskilled laborers in the US Army”, 
so it’s hard to get a handle on what they wore in 1943.
The air operations interest me the most. The thought of flying P-38s, P-39s, and B-24s under the conditions of the North Pacific gives me the willies.
Regardless of their specialties, Army Engineers are pretty skilled soldiers. I think “General Services” is a euphemism for “Loading and unloading cargo, digging ditches, laying pipes, et cetera.”
Thank you for both of your efforts/interest. I’ll do a bit more of my own research today too based on the leads you’ve uncovered.
The pants look like they may be oilskin or waxed cotton like a fisherman might wear. Not regulation but certainly something that would be widely available in 1940s Alaska.
Not sure if I’d call this final or not, but it’s all or nearly there…
Color definitely looks less like a Civil War picture and more like WWII 
I guess I’m getting used to seeing WWII in color.
It doesn’t quite look right on all monitors so will probably revisit it and play with contrasts etc.
The beanie hats are far too dark green. They are more of a light apple green.
I’d rather you didn’t do this at all, it’s falsifying history and it’s at best only a guess (and you can see radically different versions of a picture from around the world on the web showing other peoples’ guesses)
Artists have been doing drawings and paintings of historical events for a long time. As long as there is a caption notifying the viewer that the colors are added, I don’t see a problem.
Thanks for the tip on the hats.
It’s just a bit of fun - I’m not going to publish it in any history books.
Professional colourists do an enormous amount of research to try to achieve accuracy and their work serves to bring history to life and can help it find new audiences or deepen peoples understanding of history - which I would say is a good thing.
For instance:
The colourised image of this teenage victim of Auschwitz was one of the things that inspired me to start playing around with this: https://facesofauschwitz.com/gallery/czeslawa-kwoka/
I nearly chose an image from the holocaust but that felt too demanding and serious a subject to take on when I’m still learning…
As it happens, I just saw a colorized version of some men on the beach of Iwo Jima after the landing. The golden sands of Iwo Jima …
You’re kidding, I assume. 
The beach on Iwo Jima was black volcanic ash, IIRC.
I wish I was.