Speciman Stamp For US 981

My quandary is which stamp is the specimen I should chose for US stamp 981. Of four stamps the one on the top left of the four stamps is whiter compared to the the other 3. The next picture of the back of these fours stamps clearly shows that the back of this stamp is whiter than the other 3. The gum of the stamps from this era appears to be of the tanner appearance of the 3 other stamps. Also the picture of the stamp in the recent Scott catalogue appears to indicate that the color of the stamp is blue green throughout the stamp. So 2 questions. 1. Is the white coloration correct for this stamp? 2. Are the pictures of stamps in the Scott catalogue considered appropriate to the classification of the stamp?
Thanks!

I would not worry about the paper or gum colors of a 77 year old minimum value stamp. For me, I would choose the one with the best centering. If you don't like it you can always spend another ten or twenty cents and change it. Heck, I can send you blocks of these for free since I have lots that I use for postage. You need 50 quality posts though.

As for Scott catalog images, they aren't meant to be used for determining colors other than at a 35,000 foot level.

As long as there are no hidden flaws, I always pick the one that looks the best from the front to display. To me, it looks like the one on the bottom left (with the image rotated 90 degrees as you posted it).

All 4 stamps look sound and are all good "specimens" to display. Can't really go wrong.

Thank you these insights on selecting a stamp, especially for the 3 cent denomination stamps. I don't quite get the rotation comment as all four stamps as I view them are presented the same. Anyone else viewing a rotated image?
Thanks again.

In the Chrome browser, it looks correct, but in Safari (Mac) the picture is sideways.

I see this happen with other posts as well, not just yours. Did you use a phone or a scanner to take this picture?