Mostly dark brown but when you tilt it just right you end up with a cool purple shine. Luster is very nice but I photographed it with the color in mind. The reverse was more challenging and I had depth of field and lighting issues for sure with a bit of tilting. This came raw via bad eBay photos. I received a 1962 raw in the same package but instead of purple, it is blue and has a lot more color than the purple but the photography was quite difficult and something I will have to revisit another day.
If you examine a TON of Proof Sets from 1960-1964 it is possible to find crazy color nickels. Other years too but 1960-1964 are the most common. The mint packs were heat sealed...so heat, gas, the plastic itself, then when the plastic breaks down over 40-60 years and that combined with different storage environments...crazy things happen. Crazy toned nickels reside in ANACS Yellow Label Holders and Blue Label Holders, PCGS old holders and new holders, NGC new holders for sure, some of the nickels are even blessed with QA stickers. Could some of them have been "helped along" in their toning? Sure, anything is possible but I know what tends to be market acceptable and what has made it into all of the TPG Holders. They are beautiful cheap thrills within US Coins!
Here's my 1996 ASE my grandma got me the year I was born. It's still white on the reverse but the obverse has a gold/orange peripheral coloring around the rim.
Picked these out of the junk bin. They were $6.50 each if I remember. I put them in my for fun album of bens and walkers I have found at banks and work.