Is there a chance that my skin might be discolored after labiaplasty?

No: If done correctly there should not be any change in color. There several techniques for labioplasty. One of them will preserve the labial edges, if that is your concern. Other patient may not like the color of there labia. In this case labiaplasty can be done in a way we eliminate this edges.

Not usually: Infant, a labiaplasty or labia reduction is typically performed to reduce unwanted darkened or hyperpigmentated skin.

Yes but unlikely: Any skin-related surgery can have scar tissue or pigment change as potential side effects. It is very uncommon in my experience though.