French Black Maran X Light Sussex

it will be lighter than the egg the cockerel hatched from. Do you know the colour of the shell?

Hens have coloured eggs depending on breed. so most add colour to the outside of the shell, unlike legbars which colour added to shell before being formed.
could you get hold of maran hens, specialist hatchery might be able to help.

So after hatching this cross, you will need to wait for a hen to lay before knowing egg color.