We've all wandered why a certain object looks the way it does. Let us take the picture above for example, under white light, combination of different lights of different wavelengths in the electromagnetic spectrum, is perceived as color Red.
First, Let me pose a question! Pretty sure, most of us have been to the supermarket or a fancy store. They keep those fancy stuffs in some kind of light, making it look all shiny and bright. You like it, expensive it may be, say you buy it. Then you go to your home, excited, waiting to tell your folks, how you bought this golden looking thing. You get them pretty hyped and after all the created drama and suspense, you open it. To your dismay, it looks Silver. Has this ever happened to you?
The color we observe is the frequency of light that didn't get absorbed by the object. Also can be depicted from the image above. When the light in the visible spectrum, composed of seven different colors, strikes the shirt, as shown above, Red gets reflected whereas every other color gets absorbed and this is what gets perceived by our eyes. Same for the shorts.
But if we look at these objects in different light settings, it would appear different. Because the setting used might not have red color in its wavelength. Suppose we take a setting that have all the other wavelengths without that of the color red. What color would the shirt or the flower above appear? Since, everything gets absorbed, it would appear black.
In conclusion, even though the color of the objects come from their elemental composition, we can still make it look different by using different light source, as different setting would reflect back different wavelengths.