I have scanned a couple of my early 37s as you guys suggested someone should. I don't know if this is of any help as you already noted the huge impact scanners and computer screens have on perceived colors...
As for your initial question wert, I also think it is a regular 37. It is not, strictly speaking, impossible that this stamps has been used 18 years after it's issue, but I think that unless proven otherwise, it is highly improbable.
One way I find useful to distinguish copper/indian red 3 cents from others is by paper type. I'm not, repeat NOT!, a paper expert, far from it! I always had, and still have, a hard time distinguishing between them, but the paper on the early 37 is "easy" to single out on most occasion as it is the same paper that was used on many Large Queens. You can often see the mesh on these papers, and it also have a shine to it that you will not find 1872 onwards.
So when I try and ID my early 37s, I usually flip over a couple of 3 cents Large Queens and see if there is any family resemblance.
It is not always conclusive and you always have to check for other printing characteristics, but that's something I have found usefull from time to time.
I also use the Morris color guide for the Small Queens, it is invaluable!
So here are the scans :
Please note that the name I use to describe the colors are from Hillson and Nixon's book.
The first stamp is dated MR 70, the others are, in my opinion, variations of the same
Copper/Indian red shade (37b).

The first stamp on the following picture is dated OC 17 1870. The others are variations of the same
Pale dull rose found mid to late 1870. I've seen people tag those as 37a.

This stamp is probably a
Dark rose on thick paper (37i) that can be found early 1871.

The first stamp is dated 1871. They both are shades of
Rose-carmine (37a) typical of that year.

The first stamp is dated SEP 72. Both stamps are the
Rose red shades from late 1871 through 1872 - early 1873 (still 37a).

1873 begins to show the shift towards orange and marks the end of the first Ottawa period. The left stamp is dated AP 3 1873. It's color is just a bit less rose / just a bit more red than the two previous 1872 stamps I've shown. I would still call it
Rose red (37a), but some would say it is 37c.
The right stamp is dated JY 7 1873. I don't know if it will show on monitors, but there is not much rose left anymore. Orange is showing through and I think it is
Dull red (37c).

This last stamp is dated AU 6 74 and is
Orange-red (plain 37)

Compared to one another :

Please keep in mind that there might be mistakes in what I have shown. It is my opinion, based on references and observations I have made, and it is the state in which my collection is in at the moment (and anyone that collect Small Queen knows how stamps move from one page of the album to another over time. It sure does in mine anyway!

)
Hope this helps!