In this first pair, a quick portrait snapshot of Sue, I have no trouble locking my eyes on Sue in the b&w, but I find them pulled/distracted a bit by the surrounding colour in the colour version. Do you get the same result?
I also get a similar effect with the next pair. My eyes pull away from the central humans and dog in the colour version, but I find them wandering much less in the b&w version.
In both cases, I don't think it's a huge deal, but I do find it interesting to note.
------------------- a note in passing ------------------
I have removed both Moderation and Captcha on my blog. If you recall, I added them recently to try to stop some spam. I haven't had to resort to this in over 10 years of blogging, but a couple of spammers were becoming annoying.
Moderation didn't work. Well, it did in the sense that I could delete their comments before they appeared, but it's not hard to delete comments after they appear. The point is that the spammers were still trying.
My next steps were to (1) shut down comments on the posts they seemed to be targetting, and (2) enable Captcha.
Something worked, and I am testing removing both Moderation and Captchas.