How do you make a fading led with 8 different colors I already made a blinking led every 1 second. Can you give me an idea how am I going to fade it every time it switch?

const int red = 5; 
const int green = 6; 
const int blue = 9; 

void setup() { 
// put your setup code here, to run once: 
pinMode(red, OUTPUT); 
pinMode(green, OUTPUT); 
pinMode(blue, OUTPUT); 
 
}  

void loop() { 
lightMe(red); 
lightMe2(red, green);  // yellow 
lightMe(green); 
lightMe2(green, blue);  // cyan 
lightMe(blue); 
lightMe2(blue, red);  // magenta 
lightMe3(red, green, blue); // white 

 
} 

void lightMe(int pin){ 
digitalWrite(pin, HIGH); 
delay(1000); 
digitalWrite(pin, LOW); 
delay(500); 
} 

void lightMe2(int pin1, int pin2) { 
digitalWrite(pin1, HIGH); 
digitalWrite(pin2, HIGH); 
delay(1000); 
digitalWrite(pin1, LOW); 
digitalWrite(pin2, LOW); 
delay(500);  
} 

void lightMe3(int pin1, int pin2, int pin3) { 
digitalWrite(pin1, HIGH); 
digitalWrite(pin2, HIGH); 
digitalWrite(pin3, HIGH); 
delay(1000); 
digitalWrite(pin1, LOW); 
digitalWrite(pin2, LOW); 
digitalWrite(pin3, LOW); 
delay(500);  
} 

How do you make a fading led with 8 different colors I already made a blinking led every 1 second. Can you give me an idea how am I going to fade it every time it switch?

const int red = 5; 
const int green = 6; 
const int blue = 9; 

void setup() { 
    // put your setup code here, to run once: 
    pinMode(red, OUTPUT); 
    pinMode(green, OUTPUT); 
    pinMode(blue, OUTPUT);  
}  

void loop() { 
    lightMe(red); 
    lightMe2(red, green);  // yellow 
    lightMe(green); 
    lightMe2(green, blue);  // cyan 
    lightMe(blue); 
    lightMe2(blue, red);  // magenta 
    lightMe3(red, green, blue); // white 
} 

void lightMe(int pin){ 
    digitalWrite(pin, HIGH); 
    delay(1000); 
    digitalWrite(pin, LOW); 
    delay(500); 
} 

void lightMe2(int pin1, int pin2) { 
    digitalWrite(pin1, HIGH); 
    digitalWrite(pin2, HIGH); 
    delay(1000); 
    digitalWrite(pin1, LOW); 
    digitalWrite(pin2, LOW); 
    delay(500);  
} 

void lightMe3(int pin1, int pin2, int pin3) { 
    digitalWrite(pin1, HIGH); 
    digitalWrite(pin2, HIGH); 
    digitalWrite(pin3, HIGH); 
    delay(1000); 
    digitalWrite(pin1, LOW); 
    digitalWrite(pin2, LOW); 
    digitalWrite(pin3, LOW); 
    delay(500);  
}