Colors may be specified in three ways: 1) RGB triplets, 2) by name, or 3) by HTML notation.
An RGB triplet is a 1x3 vector where each value is between 0 and 1 inclusive.
The first value represents the percentage of Red, the second value the
percentage of Green, and the third value the percentage of Blue. For example,
[1, 0, 1] represents full Red and Blue channels resulting in the color
Eight colors can be specified directly by name or by a single character short name.
HTML notation is a string that begins with the character ‘#’ and is
followed by either 3 or 6 hexadecimal digits. As with RGB triplets, each
hexadecimal number represents the fraction of the Red, Green, and Blue channels
present in the specified color. For example,
the color magenta.