Migo, you stated back on page one you had a blue Orpington cock in same pen as the splash Orpington cock. The blue and black chicks you begot were sired by that blue Orp cock.
Splash and splash only beget splash. There is no Lavender unless you had a Lav. parent somewhere in generations back. Comb color and egg color have nothing to do with it. Lavender is a different gene than the blue gene. The blue gene is a dominant gene that stacks. One copy will express blue, two copies express splash. Lavender is a recessive gene that requires two copies to express.
It would be great if you hatched from only the splash cock over your splash hens to prove or disprove any thought of lavender being in those birds at all. If there and each of the birds have one copy of it then 25% of the birds would hatch lavender.