I know this is likely trivial, but I cannot find the background image that you see when you wake the computer up from being idle (when the screen is locked and you have to enter in your password to return to the desktop). It's the 'mint green' image that is similar to the one loaded in the grub menu. I want to modify/replace it with something a little less noisy. I've searched around a bit, but found nothing. A search of the images on the computer was also fruitless because I don't necessarily know what I'm looking for. Thanks in advance for any help a minter can give!