Colors

I read in a book (which is not my area of ​​expertise, but rather as a side note) that since colors are specific wavelengths that are absorbed by the eye, and since there are many things that affect the wavelength (angle of the light source, temperature, etc.), the eye was supposed to perceive different shades in the same object each time, but the brain makes ‘corrections’ to what the eye transmits according to what it expects to see. Really? I don’t know if the description I gave coincides with what is described in the book, but that’s what I understood.
What interests me is the tendency to see blood and wounds, etc., and if that is indeed the case, it turns out that my expectations have a major influence on what I see and what I reject.
I would be happy to have a physical examination on the subject. thanks!