1. Color
White light is not a single color; it is made up of a mixture of the seven colors of the rainbow.
We can demonstrate this by splitting white light with a prism:
This is how rainbows are formed: sunlight is “split up” by raindrops.

2. The colors of the rainbow:
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Remember: Roy G. Biv !!!

3. Light from the Sun
The light from the sun contains a grand mixture of electromagnetic waves of varying frequency (i.e. wavelength)
The spectrum of light is characteristic of the TEMPERATURE of the sun!

4. Wavelengths of Light Red Light – l = 680 nm Green Light - l = 500 nm
Blue Light - l = 470 nm

5. Adding colors
White light can be split up to make separate colours. These colours can be added together again.
The primary colours of light are red, blue and green:
Adding blue and red makes magenta (purple)
Adding blue and green makes cyan (light blue)
Adding red and green makes yellow
Adding all three makes white again

6. Only red light is reflected
Seeing color
The colour an object appears depends on the colors of light it reflects.
For example, a red book only reflects red light:
Homework
White
light
Only red light is reflected

7. (or red and blue, as purple is made up of red and blue):
A pair of purple pants, in addition to being ugly, would reflect purple light
(or red and blue, as purple is made up of red and blue):
Purple light
A white hat would reflect all seven colors:
White
light

8. Using colored light
If we look at a colored object in colored light we see something different. For example, consider the outfit below – I mean, from a physics standpoint, not as a fashion choice:
Shirt looks red
White
light
Shorts look blue

9. In different colors of light this kit would look different:
Red
light
Shirt looks red
Shorts look black
Shirt looks black
Blue
light
Shorts look blue

10. Using filters Red Filter
Filters can be used to “block” out different colours of light:
Red Filter
Magenta Filter