using a method to resolve a chess tile colour

I have been looking for a while but people seem to be waaaaay ahead of me on on the chess front. All i want to do is have a method in a class to resolve the colour of a tile but my colour keeps coming up as "null".

import java.util.Scanner;

public class ChessTileTest {

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);

    String tileColour;
    chessTile test = new chessTile();
    System.out.print(" Enter chess move : ");
    String move = in.next();
    tileColour = test.setColour(move);
    System.out.println(tileColour);


}

}

public class chessTile { private String colour; private String address;

public chessTile(){

}
public String setColour(String move){
char letter;
int number;
letter = move.charAt(0);
number = move.charAt(1);
if((letter=='a'||letter=='c'||letter=='e'||letter=='g')&&(number/2==1)){
    colour = "Black";
}
else if((letter=='a'||letter=='c'||letter=='e'||letter=='g')&&(number/2==0)){
    colour = "white";
}
else if((letter=='b'||letter=='d'||letter=='f'||letter=='h')&&(number/2==1)){
    colour = "white";
}
else if((letter=='b'||letter=='d'||letter=='f'||letter=='h')&&(number/2==0)){
    colour = "Black";
}
return colour;
}

}