Hello!
I would like to create if potentiometer value is 0 - 341 to get green LED brightness from 0 to 255. Then if 341 - 682 to get red LED brightness from 0 - 255 and if 682 - 1023 to get yellow LED from 0 - 255.
How to do that?
Thanks! 
Something like...
int potVal = analogRead(potPin);
if (potVal < 342)
{
 analogWrite(greenLedPin, map(potVal, 0, 341, 0, 255));
}
else if ((potVal > 341) && (potVal < 683))
{
 analogWrite(redLedPin, map(potVal, 342, 682, 0, 255));
}
else
{
 analogWrite(yellowLedPin, map(potVal, 683, 1023, 0, 255));
}
might get you started.
Thanks!