My ghost shrimp are turning a bluish green color. I've had ghost shrimp for years and have never seen this before.
I've seen something kind of like that once, then the ghost shrimp ended up dying. I think it has something to do with them not being able to molt properly.
I think that's normal depending on their diet. My ghost shrimp that I have had since November 2015 has a slight greenish tint to him at times. I think maybe its because of his diet and that he grazes on the algae wafers/zucchini, etc. Other than that, he seems healthy ( This was a Black Friday sale hitchiker/Freebie ) that I never expected to live so long...............
With the minimal amount I've had in the past, any type of color change has ended up bad. I had one turn really white which led to him dying, and another that turned slightly yellow...which ended up dying. Just keep an eye out if it turns any darker.
Nothing's changed in the tank except I've been adding a biofilm supplement to give them more food to graze so maybe this is what's causing it. If it's nothing harmful it's kinda cool for them to have some color at least.