I am WAAAAY behind in reading the list. So this comment is a bit tardy but
may be helpful next year.
Several of the recipes which include colored eggs baked into bread indicate
that you can color them but not hardboil them.
I remember when my German grandmother made us such a loaf for easter and
didn't hardboil the eggs. By the time we cut the bread and opened the eggs
it was quite clear that the oven backing did not cook the eggs enough. None
of us kids would eat the bread. Fickle children.
On the other hand, my Italian grandmother (and my mother) would make egg
"baskets" from Italian cookie dough and hardboiled eggs. Complete with
green coconut grass and (sometimes) our names written on the basket handle.
It isn't a bread and don't have the cookie recipe handy but if there is
interest, I can post the recipe.