David H. Lipman wrote:

I read it when I studied ichthyology.

nice. I don't know every fish has the same sensibility to colors, it
would be interesting a diagram, a scale

In my mentioning of the leader, the transition is in the colouration
of the leader as a function of legth. A one foot section of leader
will not be monochrome but will transit, with variation in tone, from
clear red to clear blue to clear green. A classic camouflage
technique.

I didn't have any idea, thanks.
how far from the bait this transiction is put?

--
ciao
Vittorix