I2C - Slave (written for Rainbowduino) **NOT WORKING**

#include <Wire.h>
#include <Rainbowduino.h>
int rx1;  //throttle
int rx2;  //aileron
int rx3;  //elevation
int rx4;  //rudder
int rx7;
int rx8;
void setup() {
 Wire.begin(2);                // Start I2C Bus as a Slave (Device Number 9)
Wire.onReceive(receiveEvent);
 Serial.begin(115200); Rb.init();

  rx1 = 0;
  rx2 = 0;
}
unsigned char x,y;
void loop() {
  //If value received is 0 blink LED 1
  if (rx1 > 1700) {

    for(x=0;x<8;x++)
    {
     for(y=0;y<8;y++)
      {
      Rb.setPixelXY(x,y,random(0xFF),random(0xFF),random(0xFF)); //uses R, G and B bytes
      }
    }}
    else{
      Rb.blankDisplay();}
  }