Hi,
My experience speckled sussex change in colour as they get older, more white.
I would also suggest get as many cockerals as you can handle
We got through 3 cockerals before we found one that produced a quality chick.
We sell our show stock hens at 8 weeks for £38
We don't sell the cocks otherwise we would then have competition
Sussex breeding is stressful
20% don't hatch
40% cocks
20% mortality
20% hens
Sussex and Marans are about the same mortality rates,
our legbars are less than 5% mortality and below 10% unhatched
If we didn't have a waiting list for the Sussex and Marans I'd have given up by now.