I've been trying to create a library for processing but I don't understand how tu use processing types and methods in my library

here a simple example of what I want to do:

1. import processing.core.*;
2. public class Point
3. {
4. int x,y;
5. color c;
6. public Point(int ax, int ay, int ar, int ag, int ab)
7. {
8. x = ax;
9.                 y = ay;
10. c = color(ar,ag,ab);
11. }
12. }

two lines with yellow background give me an error, but I can't find a solution.

first says: color can not be resolved as a type

second one: The method color(int,int,int) is undefined for the type point