Break between two LED commands with millis

Projects General Guidance
1 
digitalWrite(whiteLedPin, HIGH);
  whiteLedChrono = millis();
  whiteLedOn = true;
  if (whiteLedOn && (millis() - whiteLedChrono >= onDuration)) {
    whiteLedOn = false;
    digitalWrite(whiteLedPin, LOW);
  }
  digitalWrite(blueLedPin, HIGH);
  blueLedChrono = millis();
  blueLedOn = true;

I want put a 1 second delay between two LEDs. Both are on simultaneously, not consequetively. Any help please`Preformatted text

2 
digitalWrite(whiteLedPin, HIGH);
delay(1000);
digitalWrite(whiteLedPin, LOW);
digitalWrite(blueLedPin, HIGH);
delay(1000);
digitalWrite(blueLedPin, LOW);

Without more context, or your entire sketch, the above will work perfectly fine.

3

If this code is in the loop() function then it appears both LEDs will be on simultaneously all of the time. If these are code fragments then it will be hard to structure a solution for you without seeing the structure of your entire sketch.