const int pwm[]={3,5,6,9};
int i,j;
const int brightness[][4] = {{255,0,0,0},
                             {100,255,0,0},
                             {50,100,255,0},
                             {5,50,100,255},
                             {0,5,50,100,},
                             {0,0,5,50},
                             {0,0,0,5},
                             {0,0,0,0}};

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:
  for(i=0;i<8;i++) {
    for (j=0;j<4;j++)
      analogWrite(pwm[j],brightness[i][j]);
    delay(500);
  }
}