NASA
Nasa: Imagine the Universe: What's the Frequency, Roy G. Biv
In this very detailed lesson plan from NASA, students investigate wavelength and frequency within the electromagnetic spectrum.
Physics Classroom
The Physics Classroom: Refraction and the Ray Model of Light: Rainbow Formation
Understand the physics behind Roy G. Biv, and how rainbows are formed by drawing upon our understanding of refraction, internal reflection, and dispersion.
NumberNut
Number Nut: Basic Topics: Shapes, Symbols, and Colors: Colors
A short explanation of how we see color and what each of the primary and secondary colors symbolize.