“Wonder is the beginning of wisdom.” - Socrates
The Processing website has resources (tutorials, references and examples) here:
https://processing.org/
The fill() function accepts:
Reference for the color datatype:
color / Reference / Processing.org
Example:
color c = #FF00FF; //Fuchsia
color[] col = {
color(255, 0, 0), // Red
0xFF00FF00, // Green
#0000FF, // Blue
c
};
:)