Arie,
Those pullets are nice looking. The males are too and I think it's interesting that the females seem to have carried over more of the Leghorn type where the males are showing the Dutch characteristic of the lower wing carriage. The males look like they have nice lobe color. All in all, it looks like a successful cross. I'll be interested to see how the back crosses to Leghorns turns out. Those pullets will be worth their weight in gold in providing a good foundation for color. I bet they have real nice undercolor too. IMO good sound undercolor lends nicely to even top color and does wonders for eliminating white in wings and tails.
Tom