//GREEN-PB0 RED-PB2 BLUE-PB1
int redPin = PB2;
int greenPin = PB0;
int bluePin = PB1;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  //R:0-255 G:0-255 B:0-255
  colorRGB(random(0, 255), random(0, 255), random(0, 255));
  delay(1000);
}

void colorRGB(int red, int green, int blue) {
  analogWrite(redPin, constrain(red, 0, 255));
  analogWrite(greenPin, constrain(green, 0, 255));
  analogWrite(bluePin, constrain(blue, 0, 255));
}