That's an Issue with your Physical Monitor and/or the Video Drivers you have, see if you can download an update for your drivers.
I've seen this happen on a few laptops, there is nothing really wrong, it's just your Monitor interacting with the driver during bootup. Unless it keeps happening, and starts happening at random intervals in other places.
Check your SVGA connection and make sure it is screwed in tight, and if you have a Laptop, boot to windows and after you have logged in, move your Monitor panel up and down, see if it turns green for an instant. If it does this, then the Inverter is bad, if it;s a new laptop bring it back cos it has defective hardware.