RGB LED simulation with Arduino code

Question

In this Arduino code, I want to when press numbers from 0 to 8, my LED s respond to it. Everything is working fine from 1 to 6 and 8. But when I select 7 and my code doesn't run well and Red and Green breathing interferes with each other. I don't understand why my 7th function doesn't work properly and it mixes to green ?!. I would appreciate you if you could help me to find out my code issue.

  int brightness = 0;    // how bright the 9 is
  char data = 0;            //Variable for storing received data
  int fadeAmount = 5;    // how many points to fade the 9 by
  int pinSelector;
  
  void setup()
  {
    Serial.begin(9600);   //Sets the baud for serial data transmission                               
    pinMode(10, OUTPUT);  //Sets digital pin 3 as output pin
    pinMode(9, OUTPUT);
    pinMode(5, OUTPUT);
    pinMode(3, OUTPUT);    
  }
  void loop()
  {
    if(Serial.available()>0 )      // Send data only when you receive data:
    {
     data = Serial.read();        //Read the incoming data send via serial monitor & store into data
     Serial.print(data);          //Print Value inside data in Serial monitor
     //Serial.print("\n"); 
     Serial.println();       // print an empty line       
  
   if(data == '1')          //Do looping so that when '1' send via serial monitor, the 9 can blink
   {
    digitalWrite(5, HIGH);
    Serial.print("9 is On");
    Serial.println(); 
   }            
   
   if(data == '2') 
   {        
     digitalWrite(5, LOW);    //If value is 0 then 9 turns OFF
     Serial.print("9 is Off");
     Serial.println();
   }
   if (data == '3')
   {
     analogWrite(9, 1); 
     analogWrite(3, 1);             
     analogWrite(10, 254);    //If value is 0 then 9 turns OFF
     Serial.print("Green");
     Serial.println();       
   }
   if (data == '4')
   {
     analogWrite(3, 1);       
     analogWrite(10, 1);       
     analogWrite(9, 254);    //If value is 0 then 9 turns OFF
     Serial.print("Red");
     Serial.println();       
   }
   if (data == '5')
   {
     analogWrite(10, 1);       
     analogWrite(9, 1);       
     analogWrite(3, 254);    //If value is 0 then 9 turns OFF
     Serial.print("Blue");
     Serial.println();       
   }
   if (data == '6')
   {
     analogWrite(3, 254);       
     analogWrite(10, 254);       
     analogWrite(9, 254);    //If value is 0 then 9 turns OFF
     Serial.print("White");
     Serial.println();       
   }                          
   }

  switch(data)          //Do looping so that when '1' send via serial monitor, the 9 can blink
   {
     case '7' :
          analogWrite(3, 1);       
          analogWrite(10, 1);       
          analogWrite(9, 1);
          pinSelector = 9;
          fade();
     case '8' :
          analogWrite(3, 1);       
          analogWrite(10, 1);       
          analogWrite(9, 1);
          pinSelector = 10;
          fade();              
   } 
   }

  void fade()
  {
    analogWrite(pinSelector, brightness);
  
    // change the brightness for next time through the loop:
    brightness = brightness + fadeAmount;
  
    // reverse the direction of the fading at the ends of the fade:
    if (brightness <= 0 || brightness >= 255) {
      fadeAmount = -fadeAmount;
    }
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
  }

Answer 1

The code of '8' is executed after code of '7' due to missing break statement in the switch-case construct.