That is all well and good, but what about green and hazel eyes.
There's a mutant in the woodpile.
More seriously, I guess the green and hazel result from mixing the DNA of brown and blue eyed mates. Maybe someone with better knowledge will weigh in.
THere is no such color as “green” in mammals. Human “green” eye color is actually a mixture of brown and blue. If you look very closely at a green human eye, you will see light brown patches or specs intermingled with blue patches or specs.
“green” results when the blue outnumbers or overpowers the brown. Hazel results when the brown outnumbers the blue. Blue-green is when the brown is almost non-existant.
I don’t know what the technical explanation is for grey or steel blue eyes...or the rust brown/red eye color that is common in redheads. THe red color is most interesting to me because it seems to be exactly the same shade of rust-brown as the freckles on the face of some natural redheads.
Sometimes the percieved eye color changes with the change in intensity of light. I once knew a mediteranean guy that had dark brown eyes indoors, but in direct bright sunlight his eyes changed to a brilliant true baby blue. It was freaky.
This would certainly explain how my brother and I both have blue eyes but a different shade from our blue eyed mother and green/brown/hazel eyed father. Our eyes are darker blue than our mother's. Hers are almost clear/translucent.