Loop code without manually pressing the button
As pointed out by Delta_G, there is no point in resetting your program.
What you should do is think your program in terms of the Arduino logic:


You put in setup() the code you want to run when your program
starts.
You put in loop() the code you want to run over and over again.


In this case loop() is fairly simple, as the stuff you want to run
over and over again is the animation, thus:



void loop() {
  colorWipe(strip.Color(75, 0, 0), 50); // Red
  colorWipe(strip.Color(0, 75, 0), 50); // Green
  colorWipe(strip.Color(0, 0, 75), 50); // Blue
  theaterChase(strip.Color(75, 75, 75), 50); // White
  theaterChase(strip.Color(75, 0, 0), 50); // Red
  theaterChase(strip.Color(0, 0, 75), 50); // Blue
  rainbow(20);
  rainbowCycle(20);
  theaterChaseRainbow(50);
}


Note that I removed the call to resetFunc().

The stuff you want to do at startup is the initialization. Oh, wait. In
a comment you wrote “I want to wait for the button press”. So this also
has to be done before the program starts looping. Hence your setup()
should initialize stuff, then wait for the button press:

void setup() {
  // Initialize the strip to all piwels off.
  strip.begin();
  strip.show();

  // Wait until the button is pressed.
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  while (digitalRead(BUTTON_PIN) == HIGH)
      ; // do nothing
}