int Green = 8;
int Blue = 9;
int Red = 10;

float _RED = 0.0;
float _BLUE = 0.5;
float _GREEN = 1.0;

int slider = A0;


void setup() {
  Serial.begin(9600);
  pinMode(Blue, OUTPUT);
  pinMode(Green, OUTPUT);
  pinMode(Red, OUTPUT);
  pinMode(slider, INPUT);

}

void loop() {

  float val = (analogRead(slider) / 1023.0) * 255.0;
    
  analogWrite(Blue, val * 0.5);
  analogWrite(Red, 255.0 * max(0.0,0.5 - abs(val-_RED)));
  analogWrite(Green, 255.0 * max(0.0,0.5 - abs(val-_GREEN)));
  
  Serial.println(val);
  

}