liquid, thought fish where uglier and less colorful out of water. mostly becuase they loose their color because they are scared. just like when you put a new fish in, in the bag he is ugly sometimes and when he first gets in your tank. you seem a lot more experince than me, so just asking
If you catch a fish and take it out of the water, most don’t actual show stress/ camouflage colours like in the water.
When in stress in the bag or fresh to the tank they try to remain obscure and that is also labelled stress colours, yes they may feel fear sort of, but its not like most folks think it is!
Stress impacts or organs and blood flow and both affects colours a time goes on due to the fishes very basic adreno gland, if you could call it that, like us sort of and this action puts abundant cortisol into the blood stream like ours called adrenaline signalling the fish to shunt blood to vital parts and can look washed out and begin to die and it may take days to months for this to kill them.
The time line of full on stress that kills fish via stress related issues has to be in action for at least 48 hours and if gill functions are rapid for that time as well, the gills malfunction and the fish may go into osmotic shock and die that day or in the coming months.
Most fish when in the boat or at home as we sort them usually fire up in colouration, many look far prettier at that stage then they ever will in the tank.
Plus in sunlight or in bright lighting they look great but in standard household/shop light out of water they will not look good any way.
Quit often when the water has run off them and mucus is getting a little dryer and scale colouration is dominant, which is not good, most really look colourful.
If fish get sick they will dull, they are not sick in the hand unless it was sick for some time leading up to being held.