Hello there. My daughter gave me a hat in my favorite color blue. What is your favorite color?
Blue is actually my favorite color too, it has been since I was a kid!
You are kidding me! That is awesome! I was told in art class that the reason why the daytime sky and the deep sea looks blue is due to an optical effect called Rayleigh scattering.
Oh that's interesting, doesn't it involve light refraction and making the sky look blue to us?
Well the eye perceives it when the dominant wavelength of light is approximately between 450 and 495 nanometers.
Oh okay, that makes sense. There are so many different shades of blue, which do you prefer? 
I actually like royal blue.
I love that color, I've always personally preferred darker blue colors over lighter ones.