Hereafter the proof that Chateau Slate & White N1 fur is dominant to Chateau Cream & White N1 :
1) Tala + Ariel => Chateau Slate & White N1 :
The Chateau Slate fur comes from Tala as Ariel gives the Chateau Cream & white fur with Alona (next picture).
2) Alona + Ariel => Chateau Cream & White N1 :
3) Alona + Sael => Chateau Cream & White N2 :
Backbreading Alona and Sael's kitten (Alona 10) shows that Alona gave the Chateau Cream & White N2 fur and Sael gave the Maincoon, as Sael had a Siamese Lilac kitten with Thea (last picture)
6) Sael + Thea => Siamese Lilac :
CQFD