Question

4.) If someone has blue eyes, which macromolecule actually causes the pigment in your eyes to be blue and which macromolecule has the information to make your eyes blue?

Answer 1

Melanin is what makes the color of the eyes, skin, and hair dark. The absence of melanin makes those body parts lighter in color.  Human traits are controlled but monogenic traits, only one gene such as the eye base color whether brown or blue.