int R=3;
int B=5;
int G=6;
void setup()
{
  pinMode(R,OUTPUT);
  pinMode(B,OUTPUT);
  pinMode(G,OUTPUT);
}

void loop()
{
  digitalWrite(R,1);
  digitalWrite(B,0);
  digitalWrite(G,0);
  delay(100);
  digitalWrite(R,0);
  digitalWrite(B,1);
  digitalWrite(G,0);
  delay(100);
  digitalWrite(R,0);
  digitalWrite(B,0);
  digitalWrite(G,1);
}