Violet green is a green series budgie with a violet factor. Violet factors work as additives onto a budgies main body color, thus making them darker in color. On a green series bird it causes their body color to be a shade darker with an faint overcast hue of blue, mostly around the rump and vent.
It is possible for you to get a few surprises if you do not know what each parent bird is split for. The only thing is, with recessive mutations, each normal parent bird has to have a single copy of the same gene for you to have a small chance of it showing up in chicks.
For example, mom must be split for recessive pied and dad must be split for recessive pied in order for you to have a chance at a recessive pied chick.
Same goes for other recessive mutations.