Atticus shows this in the smallest of ways, such as with the family's ornery old neighbor, Mrs. Dubose, who makes a habit of taunting Jem and Scout when they walk by her house. Just hold your head high and be a gentleman, Atticus advises Jem.
As light continues to move though the atmosphere, yellow wavelengths are scattered leaving orange wavelengths. Further scattering of orange wavelengths leaves red as the predominate color of sunlight. Therefore, near sunrise and sunset, a cloud's color is what sunlight color it receives after Rayleigh scattering.
It is this scattered light that gives the surrounding sky its brightness and its color. As previously stated, Rayleigh scattering is inversely proportional to the fourth power of wavelength, so that shorter wavelength violet and blue light will scatter more than the longer wavelengths (yellow and especially red light).