Even my straight-up-purple-not-even-close-to-blue violets dont show their crazy purple colour in pictures. With all the people i've had coming to purchase budgies they always comment on 3 birds - augrens son (who i call BIG-ren as opposed to his twin brother LITTLE-ren whom i sold lol) cos he is a YF2 sky blue opaline. They love his sea green colour.
The other 2 birds they comment on without fail are my DF violet sky blue spangle boy, and my DF violet cobalt spangle girl. Both of whom i hope to breed together near the end of this year to produce more DF violets and i hope to get some DF violet normals and DF violet DF spangles out of them as well.
As for your birds, they appear to be SF violet skyblues going by the pics at least. Definately not sky blues, although there is a possibility they are poorly coloured cobalts however the feathering is not right for cobalts, the feathering is definately sky blue which can only mean they are SF violet sky blues.