Conversely, cones serve to operate in bright light and provide high-acuity color vision. As light excites these photoreceptor cells, electrical signals are sent through sensory neurons of the bipolar cells and ganglion cell axons to the bundle of nerve fibers called the optic nerve. Thus, light could be viewed as photons traveling in wave-like fashion at very high speeds. As visible light passes through a prism, the waves are bent to produce a band of colors called the visible spectrum . This spectrum progresses from red to violet.
Objects thus have color because they absorb some wavelengths and reflect others.
White objects reflect all wavelength of light and in contrast, no pun intended, black objects absorb all wavelengths. Our perception is not always reality. Degrees of color blindness exist, i.e. inability to distinguish blue from green. Some people also have highly sensitive color perception, allowing visual differences to be detected that the sensory tester may not see. Consistent responses about an object color are often given by subjects even when filters are used to mask differences.