I separated out that one with the bit of color and the biggest one without any tail markings and put them into their own tank. They are very shy now though and hide whenever I enter the room. Hopefully they will adjust enough to color up soon.
I hadn’t heard of odinium, but do you mean the same thing we call “Velvet” over here? They look a bit more relaxed now that bigger one is out of the main tank. A little one I thought was gone is back swimming around in the 20 gallon tank.