You have probably come to this page worrying because your colourful leopard gecko suddenly looks very ill and ghost-like.
But please don’t fear – this is perfectly normal and it is just a sign that your leopard gecko is about to shed its skin.
As the gecko approaches shedding time, their top layer of skin will slowly loosen, getting ready to come away from the newly-formed skin beneath. Your gecko may take on a more dusty-looking appearance maybe a day or two before a shed, and then will turn very white immediately before the shed.
Here is a photo of my gecko looking her bright and normal self with very dark spots, a little bit dusty a few days before a shed with slightly more pale dots (you have to look closely), and then very white a few hours before shedding.
The best thing you can do is make sure they have the best possible shedding environment; make sure their enclosure is humid enough (a quick spray of water will do), and make sure their moist hide is suitably damp.
This will mean their skin is more supple and easy to pull off- insufficient moisture is the main cause for a gecko having shedding problems.
Afterwards make sure there is no shed stuck on their body (you may need to help them remove it IF they can’t do it themselves).