New layers, eggs changing colors

[shellers]

So I have 12 little hens, 19 weeks old. Last week 1 RIR and 1 Black Australorp started laying. This week I think one of the other RIR's is laying. Initially the shells were a deep dark brown and shiny. But yesterday and today 2 of the eggs are pale pink and dull. Is this normal? Should I change any diet issues? I did start adding a little more Apple Cider Vinegar to their water, could that have been the change? Also, at least 9 of my little hens seem a lot crabbier! Like having a dozen 13 yr old girls stuck in a cabin at summer camp! Is this normal hormonal stuff? Can't imagine them being this ornery and being stuck in a coop during a Montana winter! They were so sweet just 2 weeks ago!

 

[chfite]

I have 8 hens: 3 New Hampshire Reds, 4 Barred Rocks, 1 Buff Orpington. I get brown eggs of varying shades all the time. From time to time, I get a white egg. The color depends upon how much coloration the hen deposits on the egg when she lays it. I get eggs with spots and squiggles, too. The intensity of the color will change depending upon how long the egg sits in the nest, too.

They all taste the same.

Mother Nature is real big on variety.

Chris

 

[shellers]

Nature is cool for sure! Just wanted to make sure I wasn't doing anything wrong. Thanks for the encouragement