There are various ways to use colours in Processing since Processing is very flexible with colour formats.
RGB and RGBA
This is the standard RGB(A) notation and the default color mode. The first three colour values (red, green, blue) range from
255. For example, the below example is the colour red since red is maxed out at
255 while the others colours are at
0. White is at
(255, 255, 255) and black is
(0, 0, 0). The optional 4th parameter indicates the alpha value -- i.e. transparency. As in other the components, the range of values is again [0-255];
0 being completely transparent and
255 being completely solid.
color(255, 0, 0) // This is red color(0, 255, 0, 255) // This is opaque green, and is the same as color(0, 255, 0) color(255, 255, 0, 10) // This is almost transparent yellow
HSB notation is similar to RGB notation, except for the fact that red, green, and blue are replaced with hue, saturation, and brightness, respectively. You can switch into HSB by using
color(0, 0, 255) //This is white
As with RGB, HSB also has the alpha value as the fourth parameter.
If one parameter is specified to a color function, it will be interpreted as the amount between black and white. White is represented as 255, and black as 0. It is the same as
color(param1, param1, param1) in RGB mode. If two parameters are specified, then the first parameter will be interpreted as above and the second will be the alpha value.