Every color on a computer screen is made by mixing red, green, and blue light. Each of the three colors can be adjusted to 256 intensities, from 0 to 255, which makes a total of
dot rgb(176, 224, 230), 150
The program above specifies a light blueish-greenish color that includes red with intensity 176, green with intensity 224, and blue with intensity 230.
Another way to write an RGB color is to use a CSS hex color code.
Convert each of the components to a two-digit base-16 number, and
then put them together in a string with a
Adding light colors can sometimes be unintuitive: for example, red
and green make yellow. For an alternative to
hsl, which allows you to specify colors by hue.
rgba function can be used to create a partially
transparent color code. The fourth component "a", or "alpha"
value is an opacity level from 0.0 to 1.0 that determines how the
color is mixed with the colors "underneath".
So, for example, if a green dot is drawn with alpha 0.5, it is blended with the colors behind it:
bk 100 dot red, 200 fd 200 dot blue, 200 bk 100 dot( rgba(0, 255, 0, 0.5), 200)