void setup() {

// initialize digital pin 5,6,7 & 8 as an output.

pinMode(5, OUTPUT);

pinMode(6, OUTPUT);

pinMode(7, OUTPUT);

pinMode(8, OUTPUT);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH); }

// the loop function runs over and over again forever  

// Here the as pin 8 is common anode

// As pins 5 and 6 are set to HIGH,the diodes connected to

//blue and green LED are in reverse biased condition

//therefore only the Red colour will be seen on the RGB LED
void loop()
{
digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, LOW);

digitalWrite(8, HIGH);

delay(500);

// Here the as pin 8 is common anode

// As pins 6 and 7 are set to HIGH,the diodes connected to

//blue and red LED are in reverse biased condition therefore

//only the Green colour will be seen on the RGB LED

digitalWrite(5, LOW);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

delay(500);

// Here the as pin 8 is common anode

// As pins 5 and 7 are set to HIGH,the diodes connected to

//red and green LED are in reverse biased condition

//therefore only the Blue colour will be seen on the RGB LED

digitalWrite(5, HIGH);

digitalWrite(6, LOW);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

delay(500);

//Further mixture of colours can be produced by switching on any 2 colours at the same time

}