The color question keeps coming back and probably would forever.
If you’re just paddling you probably want a bright yellow kayak that will be the most visible to fast motorboats drivers.
If you’re hunting or bird watching you’d better choose a dark green or camouflaged kayak, for obvious reasons.
The answer becomes more complicated when it comes to fishing – From an underwater perspective the color of a surface object is a minimal issue. Flash and shine are more likely to cause a reaction among fish, as well as sudden motion and noise. Having said that, you can try and improve the odds:
Regardless of what colors various fish species are capable of discerning, what we know and can test for ourselves is that when you’re in the water you usually perceive the bottom to be dark, and when looking upward you’re actually looking at a source of light – whether it is strong of feeble, depending on circumstances.
In fact, nearly all fish have their back darker than their bellies, so that they would blend in with the bottom when looked upon from above, and blend in with the sky when looked upon from below.
So far, the answer seems to be ‘choose a fishing kayak that has a light bottom’, doesn’t it? -Well, not necessarily, because color (or brightness, actually) is only part of what fish can see and react to.
The other thing (besides motion) is the basic form of your kayak: Like all animals who fear predators, fish can instantly discern a pattern that looks like a predator and react to its presence automatically by either swimming away or hiding. There is no thought whatsoever involved in such pattern recognition process – It’s just a basic physiological reflex.
Your kayak’s contour on the bright sky background can easily fit into a ‘Predator’ pattern because the form of a traditional monohull kayak is basically one of a fish. In fact, one of the two basic monohull forms is called ‘Fish’, and the other is called ‘Swede’ and it is identical to the Fish form except for the fact that the kayaker is facing the other way…
So, it would make sense to try and ‘break’ this fish-scaring pattern by camouflaging the bottom of your kayak to make it look like something else, such as floating branches or flotsam.
From this aspect, the bottom of a W kayak looks like two straight and parallel objects not alike a fish form. This is a somehow better start, and whether you choose a bright colored W Kayak to blend with the bright sky background or a dark W Kayak to make its contour resemble even less to a predator fish is up to you.