Hi, you can use an array as a type or even a PVector or a custom class. LIke:

" or a custom class"
Which is already there, it is called coulour!
Note: traditionally in Java, we name the classes with an initial uppercase letter and the variables with an initial lowercase one... Your style is a bit disturbing...
Note that you can do:
void draw() {
 
  count(Red);
  count(Green);
  count(Blue);

}

void count(colour c) {
    if (c.CountingDirection==1) c.Colour++;
    else c.Colour--;
    if (c.Colour==255) c.CountingDirection=0;
    if (c.Colour==0) c.CountingDirection=1;
}

Note also that your code cannot work, as your class has no (shown) constructor.

Thanks guys
I'm new to Processing and Java. I only coded in C before, so i have much to learn

Ok i tried to initialize the colours with values, but it doesnt work this way. I couldnt find much help searching google.

1. public class Colour {
     int countingdirection;
     int colour;
   
    Colour() {   // is that the correct constructor?
     }
   }
   
   Colour Red = new Colour (1,0);
   Colour Green = new Colour (1,50);
   Colour Blue = new Colour (1,100);

Do you have a good online tutorial you can recommend?

" Do you have a good online tutorial you can recommend?"
http://processing.org/learning/ => Objects

1. public class Colour {
2.   int countingDirection;
3.   int colour;
4.  
5.  Colour(int cd, int c) {
6.     countingDirection = cd;
7.     colour = c;
8.   }
9. }