Colors are About Reflection
The colors you see are reflected from objects. Something like a green plant actually absorbs most of the colors in white light and reflects the green. It's the green (the reflected) color that you see. A red rose reflects red and absorbs the other colors. The colors your eye can see are from a narrow band of something called the electromagnetic spectrum (EM Spectrum). You will hear scientists talk about Roy G. Biv. That's not some guy who discovered light, those are actually all of the colors of visible light you can see. ROY-G-BIV stands for Red, Orange, Yellow, Green, Blue, Indigo, and Violet.