Yes, of course they work at night/in coloured water as even unflavoured fake baits (I only use unflavoured because they work well) will give off a scent that will/may attract the fish due to their makeup and the only way a fish will find out if it is edible is to take it in it's mouth......This is all very well but what about fake baits at night or in coloured water? They still work, sometimes without any free offerings.
Also, fish are quite able to demonstrate preferences. They will not necessarily respond to all baits or varieties in the same way.
I believe your view is a little simplistic.
If I can go back to artificial flavours, fish know which ones they prefer.
It is quite plausible that they could show similar preferences for different types or makes of fake baits.