i would use a glass prism or a spectograph
Objects have different colors because of the way they reflect and absorb light. When light shines on an object, it absorbs some colors and reflects others, which determines the color we see.
They have a lower "albedo" if you will. Light objects reflect light at a greater rate than dark objects which absorb it. This is why dark objects heat up more than light ones.
the light of it that is wrong
Objects that reflect all colors of light appear white because they are reflecting the entire visible spectrum equally. When all colors are reflected, they combine to create white light. This is in contrast to objects that absorb all colors, which appear black because they are not reflecting any light.
Colored light can affect the appearance of objects by changing how the colors of the objects are perceived. When white light shines on an object, the object absorbs some colors and reflects others, which are what we see. If colored light shines on the object, it can alter the colors that are reflected and thus change how the object appears to the viewer.
The colors we see in opaque objects are produced when certain wavelengths of light are absorbed by the object and others are reflected. The reflected light is what we perceive as color. Different colors are seen based on which wavelengths of light are absorbed and reflected by the object.
Red and blue light will not absorb the same light. Red objects reflect red light and absorb other colors, while blue objects reflect blue light and absorb other colors.
This applies not only to opaque objects. The basic idea is that white light is a mixture of different colors, and objects tend to reflect the different colors - the components of white light - in different proportions. For example, an object that reflects most of the red light but not much of the other colors will look red.
Your eyes perceive different colors because of the way light is absorbed and reflected by objects. Different colors are created by the varying wavelengths of light that are absorbed and reflected by the objects you see. Your eyes then interpret these different wavelengths as different colors.
Black objects absorb most of the visible light that strikes them, reflecting very little light back to our eyes. In white light, which contains all the colors of the spectrum, black objects absorb all colors equally, appearing black to our eyes.
Darker colors tend to absorb more light and heat, whereas lighter colors reflect more light and heat. This is why objects with darker colors might feel hotter to the touch when exposed to sunlight, compared to lighter-colored objects.
Blue objects absorb wavelengths of light that correspond to other colors on the spectrum, typically orange or yellow. This means blue objects appear blue because they reflect blue light and absorb light of other colors.