Can chickens egg color change?

[Luke-4]

I have two chickens that I have had a couple years. Each hen lays an egg every day. My brown hen was laying brown eggs and the grey hen was laying blue eggs. In the last week all the eggs have been blue. Why would my brown hen change from brown eggs to blue eggs? I still get the same number of eggs. The brown hen lays wider shorter eggs that are now blue while the grey hen lays longer thinner eggs that have always been blue. The shapes have not changed only the color of the brown hen’s eggs have changed.

 

[Vsteve67]

I purchased 3 ameraucana chickens last year. They started laying blue and green eggs. So I would estimate that I've regularly gotten these colored eggs for about 8 months now. A month or so ago I thought they stopped laying for some reason. Today I was lucky enough to watch one lay an egg. The egg was cream colored. So now I'm wondering if they are actually laying eggs, but are now a different color. Is it normal for a chickens egg color to change? I always thought that what ever color they lay is what it will always be. Is it something I'm doing wrong? Everyone told me before I started with chickens that it was easy to keep a flock, but my chickens have given me a run for my money since day one. I keep them fed, they have a large enclosed run for a semi free ranging feel (bad flying predator area), the always have plenty of fresh water, just always done everything I could to keep them happy. And keeping them laying has always been difficult. Now this egg color change has knocked me for a loop. I have a flock of 24 including 2 roosters. Currently getting 2 to 5 eggs daily.

Well I thought I was going crazy too but my olive egger has always been laying greenish eggs and I seen one with my own eyes lay a brownish egg with some speckles. I can’t find any answers either.

 

[Vsteve67]

My Olive egger has always laid green eggs. I thought the Olive egger s had slowed down but I saw my olive egger lay a brown egg with speckles and was dumbfounded. I had to do a double take as to which chicken I was looking at. I have no answers either but know what I saw.

 

[aart]

My Olive egger has always laid green eggs. I thought the Olive egger s had slowed down but I saw my olive egger lay a brown egg with speckles and was dumbfounded. I had to do a double take as to which chicken I was looking at. I have no answers either but know what I saw.

Did you check the inside of the shell for a blue tint?
Open and and immediately remove the membrane from the shell, place on a white sheet of paper to detect any blue tint.

Blue tint can fade while the brown coating remains.
Post pics.