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Current time:0:00Total duration:2:34

- Although RGB triples are great for representing
how we can generate colors, they aren't natural for artists to use. Instead, we use the concept of
hue, saturation and lightness to find the exact color we need. On the hue saturation wheel, the angle around the
circle defines the hue, and the radius defines the saturation. The position in this
circle is then combined with the setting of the Lightness slider to define a final color. From now on I'm gonna
call this Lightness slider the Lightness Dimension, since it only requires a
single number to define, and this color, which is defined
using these HSL settings, is also some position
in the RGB color cube. That brings us to a key
problem in this lesson. How does each HSL setting convert into a unique
point in the RGB cube? First, let's think about
how we can go from a 3D cube to a 2D circle. The trick is to think
about where the grays are in our color cube. Anywhere in our color cube
where the RGB values are equal, we get some shade of gray. For example, 20%, 20%, 20%,
gives us this darker gray, and 80%, 80%, 80%, gives
us this lighter gray. That means there's a line
of gray within our RGB cube, meaning that there's
only one dimension needed to describe all grays. So let's rotate the color cube so that we're looking directly
down at the gray line. Does it look familiar? Mathematicians cheat a bit
and deform this into a circle. There's some fancy math to
make this stretching happen, but we'll ignore it here. And that's where the hue
saturation wheel comes from. Finally, we can get to
the Lightness Dimension. To do this, we pop back into 3D space by growing our circle into a cylinder. The Lightness Dimension defines what slice we take out of our color cylinder. A Lightness value of 50% takes
a slice out of the middle, and to lighten the shade
of any color on this wheel, we're moving up the Lightness
Dimension to a higher slice, and to darken the color, we move down the Lightness
Dimension to a lower slice. Okay, this is important,
so let's pause here. In the next exercise, we'll challenge you to think
about this model a little more. Take your time and have fun.