int lastButton = LOW;
int curButton = LOW;
int x = 0;
int red = 10;
int green = 9;
int blue = 8;
int button = 3;

int debounce(int last){
  int current = digitalRead(button);
  if(last != current){
    delay(5);
    current = digitalRead(button);
  }
  return current;
}

void setup() {
  pinMode(red, OUTPUT);
  digitalWrite(red, HIGH);
  pinMode(green, OUTPUT);
  digitalWrite(green, HIGH);
  pinMode(blue, OUTPUT);
  digitalWrite(blue, HIGH);
  pinMode(button, INPUT);
  digitalWrite(button, HIGH);
}

void loop() {
  curButton = debounce(lastButton);
  if(lastButton == HIGH && curButton == LOW){
    if(x < 7){
      x++;
    }
    else {x = 0;}

    switch(x){
      case 0:{
        digitalWrite(red, HIGH);
        digitalWrite(green, HIGH);
        digitalWrite(blue, HIGH);
        break;
      }
      case 1:{
        digitalWrite(red, LOW);
        break;
      }
      case 2:{
        digitalWrite(red, HIGH);
        digitalWrite(green, LOW);
        break;
      }
      case 3:{
        digitalWrite(green, HIGH);
        digitalWrite(blue, LOW);
        break;
      }
      case 4:{
        digitalWrite(green, LOW);
        break;
      }
      case 5:{
        digitalWrite(green, HIGH);
        digitalWrite(red, LOW);
        break;
      }
      case 6:{
        digitalWrite(blue, HIGH);
        digitalWrite(green, LOW);
        break;
      }
      case 7:{
        digitalWrite(blue, LOW);
        break;
      }
    }
  }
  lastButton = curButton;
}