Arduino Police Strobe (w/ millis())

/*******************************
* Arduino Police Lights Strobe Example
* James C4S / www.cmiyc.com
*
* How to make lights strobe like police lights using millis() (no delay)
*
* http://www.cmiyc.com/tutorials/arduino-example-police-lights-with-millis
*******************************/

// English for which LED to Strobe
#define RED 0x0
#define BLUE 0x1

// Variable to track which LED is on
byte whichLED = RED;

// Where are the LEDs connected?
const int LED_Red = 7;
const int LED_Blue = 11;

// State variables for the LEDs
byte Red_State = LOW;
byte Blue_State = LOW;

// Some delay values to change flashing behavior
unsigned long switchDelay = 250;
unsigned long strobeDelay = 50;

// Seed the initial wait for the strobe effect
unsigned long strobeWait = strobeDelay;

// Variable to see when we should swtich LEDs
unsigned long waitUntilSwitch = switchDelay;  // seed initial wait


void setup() {
   pinMode(LED_Red, OUTPUT);
   pinMode(LED_Blue, OUTPUT);
}

void loop() {
    digitalWrite(LED_Red, Red_State);     // each iteration of loop() will set the IO pins,
    digitalWrite(LED_Blue, Blue_State);    // even if they don't change, that's okay

    // Toggle back and forth between the two LEDs
    if ((long)(millis() - waitUntilSwitch)>=0) {
        // time is up!
        Red_State = LOW;
        Blue_State = LOW;
        whichLED = !whichLED;  // toggle LED to strobe
        waitUntilSwitch += switchDelay;
    }

    // Create the stobing effect
    if ((long)(millis() - strobeWait)>=0) {
        if (whichLED == RED)
            Red_State = !Red_State;
        if (whichLED == BLUE)
            Blue_State = !Blue_State;
        strobeWait += strobeDelay;
    }
}