Using this potion on a Jewelviper egg will allow it to hatch into one of its alternate colorations.
The Jewelviper potion can be used on Jewelviper eggs. Doing so will allow the egg to hatch into one of the alternate forms. Once changed, the Jewelviper cannot change back to its normal (Jet) form. The potion can be used on bred Jewelviper eggs to change it to any of the forms it isn't already.
Only one Rainbow Potion can be used per Jewelviper, so it is not possible to feed one egg multiple potions to get the desired form.