I am on an epic mission to find out why things are different colors (or at least appear to be). I have looked up how the eye works and I know it has to do with wave-lengths but I'm still super puzzled!

Because objects absorb light of different colors, depending on their chemical composition and structure. The light that is reflected into your eye — what you see — is missing these colors. You see what's left over. Chlorophyll, for example, absorbs red and blue light strongly. The green is reflected, so plants look green.

 

http://www.tutorvista.com/content/biology/biology-iv/photosynthesis/photosynthetic-pigments.php

Light travels as waves, and those waves come in different wavelengths. The eye has several different kinds of receptors, which are most sensitive to different ranges of wavelength. You perceive different colors depending on the ratio of how strongly these different receptors are stimulated.

Things "are" not of different colors. Things have the color of the light that fall on it. If you take a red lamp and light an object, the object gets red. If the light is blue, the object gets blue. Only when the light is white (solar light that contains all visible wavelengths) the object reflects some color, and absorbs some other, as explained Swansont.

Here's a cool website: Causes of Color

What a beautiful site. Thnks