Modifying a Sketch Startup Routine - different background

This question was posted by stmacarelli in the Processing Forum and now I am running into the same issue. When a processing sketch starts, it will show a grey blank screen. How can I change it to say see a black background instead?

Please note this is when a sketch starts, it cannot be solved with background() in setup within a sketch.

Many thanks…

If I run the following sketch it starts with a red background, not a hint of grey anywhere.

void setup(){
  size(300,300);
  background(0);
}

So I am puzzled to know where the grey screen comes from.

Using Processing 4.2.0

You are right … that does the trick for Processing. Works when I run a sketch on my laptop. Just discovered that the issue I have is with Processing on a Raspberry Pi and figured out is the LCD panel that gives me grief. The panel shows gray until the sketch is executing.