Red light has the longest wavelength and, therefore, the least amount of energy in the visible spectrum. Wavelength decreases and energy increases as you move from red to violet light across the spectrum in the following order: red, orange, yellow, green, blue, and violet.
As light wavelength decreases from red to blue light, so does the ability of light to penetrate water. Blue light penetrates best, green light is second, yellow light is third, followed by orange light and red light. Red light is quickly filtered from water as depth increases.