What is RGB
Task
Make the screen turn yellow!
Try changing the first three numbers ( $R$, $G$, $B$ ) to 1.0 or 0.0
Hint: you need $\text{red} + \text{green}$, but no $\text{blue}$
Theory
Most computer graphics images are defined in terms of RGB color space, where each pixel is a mix of three primary light sources:
- 🔴 Red
- 🟢 Green
- 🔵 Blue
These lights mix additively, meaning:
- you start with black ( $R=G=B=0$ );
- you add light to create color;
- full intensity of all three ( $R=G=B=1$ ) gives white.
Mixing Examples
| Mix | RGB Values | Resulting Color |
|---|---|---|
| Red | (1.0, 0.0, 0.0) |
Pure red light |
| Green | (0.0, 1.0, 0.0) |
Pure green light |
| Bue | (0.0, 0.0, 1.0) |
Pure blue light |
| Red + Green | (1.0, 1.0, 0.0) |
Warm yellow tone |
| Green + Blue | (0.0, 1.0, 1.0) |
Cool aqua tone |
| Blue + Red | (1.0, 0.0, 1.0) |
Vivid pink-purple |
| Red + Green + Blue | (1.0, 1.0, 1.0) |
White light |
| All zero | (0.0, 0.0, 0.0) |
Black (no light emitted) |
Each channel can be dimmed from:
0.0- fully off1.0- fully on
This allows for continuous blending:
(0.5, 0.5, 0.0)- muted yellow (olive)(0.2, 0.6, 0.8)- soft teal(0.9, 0.3, 0.4)- warm rose
This flexibility lets us create millions of colors on an RGB monitor.