Genetically, a Lavender Orpington is a black chicken with 2 copies of the recessive gene that turns black into lavender.
Since the lavender gene is recessive, that doesn't show in the chicks.
The chicks look the same as chicks from a Black Orpington (or any other solid black parent.)
The black is dominant over most other colors and patterns, so chicks are usually black. They can be other colors if the other parent gives them some gene that affects black: Barring, Blue, Dominant White, Dun, or in some cases chocolate.