This document is a presentation on the science of color that explores color theory, how the eye perceives color, and how the brain interprets this information. It discusses the three primary colors of red, green, and blue and how different light wavelengths are absorbed by the three types of cones in the eye, which are then processed by the brain to produce the perception of various colors. While pink has no single wavelength of light, the brain interprets a mix of red and blue wavelengths to produce the perception of the color pink. The presentation aims to explain the complex biology and mathematics behind how humans see color.

1. Why is Pink not in
the Rainbow?
The Science of Color
Dec 11th at 12pm
An introductory talk on the mechanisms
through which our eyes provide
color to our lives
Science Writer, Taylor Geomatics
Lecturer:
Maxwell Taylor
What Are the Three
Primary Colors?

4. What is
Color?

5. Color
Is
Complex
Complex Biology
Complex
Mathematics
Complex
Categorization
(This is an image of high-level
color model theory)

6. In
The
Beginning…

7. …There Was Light

8. …There Was Light

10. Different Waves, Different Colors

11. Rayleigh Scattering

12. Light
But
Why?
Different Waves, Different Colors

13. A “blue” cone absorbs light
of many wavelengths, but
peaks at around 445nm
Source of
white light
Blue
Cone
Because it absorbs the
shortest wavelengths best,
it is also called the S cone
(S for ”short”)

14. Green
Cone
Red
Cone
“Green” and “red”
cones peak at longer
wavelengths
Source of
white light
They are also know as the
M cone and L cone,
respectively
(M for “medium”)
(L for ”long”)

15. Why is the “red” cone red
if it’s peak absorption is in
yellow-green?

16. What happens when yellow-only
light enters the eye?
Amount of yellow
light absorbed
80% 50% <1%

17. 80%
50%
0%
Yellow!

18. What happens when red-only
light enters the eye?
Amount of red
light absorbed
30% 5% 0%
Amount of yellow
light absorbed
80% 50% <1%
(relative differences
between cones is as
important as total light
absorbed)
6x
1.6x

19. 30%
5%
0%
Red
!

20. Red, Green, and Blue
The
Additive
Primary
Colors
Each cone has a spectrum spot
where it alone activates brightly
while the other two cones don’t.
Meaning…

21. C olor Mixing

22. Green!
Green
Wavelength Light
Yellow!
Mix of Red and Green
Wavelength Light
Brain: “My green cone alone is
firing the most?”
Brain: “My red and green cones are
both firing a lot?”

23. Yellow!
Yellow
Wavelength Light
Pink!
Mix of Blue and Green
Wavelength Light
Brain: “My red and green cones
are both firing”
Brain: “My red and green cones
are both firing”

24. There is no wavelength of pink
Pink is an abstraction. A way
for our brains to signal the
presence of “red” + “blue”
Does that mean pink just
an illusion of the mind?

25. Is Pink …
Even Real???

28. Presentation Has Ended
You have been watching The Science of Color, an introductory level discussion by
Science Communicator Maxwell Taylor that explores color theory, the mechanics
of the eye, and how it is that our human brain provides color to our daily lives.
This presentation was brought to you by Taylor Geomatics. If you would like a
copy of this talk, please email Mr. Taylor at Taylor.Geomatics@gmail.com.
Thanks for watching!