Is this color difference between an iMac mid 2010 and iMac late 2015 normal?

In case somebody has the same question: I have just contacted Apple Support (awesome support given this is a ten years old product!); the slight colour difference is something to expect e.g. not a malfunction.

Thanks again for the reply and information.

Regarding the left screen, thanks for pointing the dark edges out! Do you think that could be dust?

However, I have double-checked the colour of my 2015-iMac by placing my new MacBook and a Dell monitor next to the 2015-iMac. The colour on the iMac 2015 is without mistake correct; it only looks pink on the picture (but as mentioned before, the edges are dark); e.g. when opening the Google homepage or a Finder window, its background is white on all screens except the 2010-Mac, which has a green tint to it...

By the way, I have set the brightness of both displays to the max - thanks for mentioning that as well.

Regarding the test picture, the colours look almost identical on both iMacs. However, the 2010-iMac has a green tint also over the test picture). Actually, I just managed to capture this by making a video (interestingly, the colours are more accurate when making a video), however, also here the 2015-iMac looks pink while, in fact, it displays a perfect white:

I am out of ideas; maybe the old iMac has a hardware issue?

Thanks for the reply and pointing out this (somewhat hidden) feature. Actually, I have already tried matching the colors with dozens of custom made color profiles, however, with no avail so far. : (

As mentioned in my reply BDAqua some moments ago, I managed to capture the displays:

As mentioned above, I have triple-checked the display of the 2015-iMac - it is definitely accurate and shows a perfect white.

I am out of ideas; maybe the old iMac has a hardware issue?

Thanks a lot for the swift reply.

Sorry, it's quite hard to photograph; the iMac 2015 only looks pink on the photograph; in real it looks fine (e.g. the background of the Google homepage is white on my late 2015 iMac, but greenish on the 2010 iMac).

Thanks for the tip regarding NightShift; I forgot to mention that I already had turned it off.

Thanks again.

Oh, I see. So I guess this is to expect?

Thanks for the tip regarding the Color Profiles; I have tried them (and also made a custom one), however, with no avail. Did you manage to match the colours? If yes, may I ask what your settings are?

Thanks a lot.

Thanks! Thankfully, for the moment it is barely noticeable. I will definitely keep an eye on that though.