Turn ON different color LEDs with Voice Command

1String voice;
2
3#define ledRed 4
4#define ledGreen 5
5#define  ledBlue 6
6#define ledWhite 7
7void setup() 
8{                                           
9  Serial.begin(9600);
10  pinMode(ledRed, OUTPUT);
11  pinMode(ledGreen, OUTPUT);
12  pinMode(ledBlue, OUTPUT);
13  pinMode(ledWhite, OUTPUT);
14 }
15void loop()  {
16 while (Serial.available())   //Check if there is an available byte to read
17  {                            
18  delay(10);                   //Delay added  to make thing stable
19  char c = Serial.read();      //Conduct a serial read
20  voice += c;                  //Shorthand for voice = voice + c
21  } 
22
23  if (voice.length() > 0) {
24    Serial.println(voice);
25   if(voice == "red")                             
26     {
27     digitalWrite(ledRed,HIGH);
28     delay(9000);
29     digitalWrite(ledRed,LOW);
30    
31     }  
32  else if(voice == "green")                              
33     {
34    
35    digitalWrite(ledGreen,HIGH);
36     delay(9000);
37     digitalWrite(ledGreen,LOW);
38     }
39  else if(voice  == "blue")                              
40     {
41    
42    digitalWrite(ledBlue,HIGH);
43     delay(9000);
44     digitalWrite(ledBlue,LOW);
45     }
46  else if(voice  == "white")                              
47     {
48    
49    digitalWrite(ledWhite,HIGH);
50     delay(9000);
51     digitalWrite(ledWhite,LOW);
52     }
53  voice="";                                                       //Reset the variable after  initiating
54  }}