Violet budgies may have violet in their tail feathers (the short ones primarily, not long ones!), although I don't know how this would show up on a green bird. I've been told this isn't accurate way to define a violet, so can't say for sure. I haven't had enough to determine one way or the other... just something I've noticed.
As an example.... blue budgie
vs Dominant pied violet factor blue (aka "white bird") - she had both blue and violet patches
Berry (♀ Cockatiel) hatched June 2017
Opal (♂ Budgie) hatched 13 August 2017
Pearl (♀ Budgie) hatched 15 August 2017
+ an aviary of 16 other budgies! all hatched 2014-2017