Again I agree with you Alessio.
When done a cross with an other race (for taking a coloration or for a better type) we can't think in 2 or 3 generations. When we do so we loose the investments of years done by breeders before us.
Was why I reacted on Rachele's question with :
"To bring in a Dominant colorations from an extern breed you need about 6 generations to come back to 98% of the original breed.
To bring in a recessive colorations from an extern breed you need about the double of generations to come back to 98% of the original breed".