Control an RGB LED with one potentiometer!

1int rPin = 6;
2int gPin = 5;
3int bPin = 3;
4int buttonPin = 13;
5int  potPin = A0;
6
7//an array holds the different modes
8String modes[3] = {"blue"  , "red" , "green"};
9String currentMode;
10
11int PWM;
12int potVal;
13
14int  greenVal;
15int blueVal;
16int redVal;
17
18bool greenState;
19bool blueState;
20bool  redState;
21
22int currentButtonState;
23int oldButtonState;
24int i = 0 ;
25
26
27void  setup() {
28
29pinMode(rPin,OUTPUT);
30pinMode(bPin,OUTPUT);
31pinMode(gPin,OUTPUT);
32pinMode(buttonPin,INPUT_PULLUP);
33pinMode(potPin,INPUT);
34}
35
36void  loop() {
37  
38
39//controls the current colour mode
40currentButtonState =  digitalRead(buttonPin);
41if (currentButtonState == 1 && oldButtonState==0){
42  i = i+1;
43  delay(50);
44
45//ensure the array loops around
46  if(i == 3){
47    i=0;
48  }
49}
50oldButtonState = currentButtonState;
51
52
53currentMode  = modes[i];
54
55
56potVal = analogRead(potPin);
57PWM = (potVal * 255./1023.);
58
59//potentiometer  sens adjustment
60if (PWM <= 20){
61  PWM = 0;
62}
63
64
65
66if (currentMode  == "red"){
67  greenState=false;
68
69   if(redState == false && PWM == redVal){
70    redState = true;
71   }
72  
73   if(redState==true){
74    redVal = PWM;
75    analogWrite(rPin, redVal);
76   }
77
78}
79
80
81if (currentMode == "green"){
82    blueState = false;
83  
84   if(greenState == false && PWM == greenVal){
85    greenState = true;
86   }
87  
88   if(greenState==true){
89    greenVal  = PWM;
90    analogWrite(gPin, greenVal);
91   }
92}
93
94
95if (currentMode  == "blue"){
96    redState = false;
97  
98    if(blueState == false && PWM  == blueVal){
99    blueState = true;
100    }
101  
102   if(blueState==true){
103    blueVal = PWM;
104    analogWrite(bPin, blueVal);
105    }
106}
107
108
109}