Is it provides for a limeblood to still be alive and hiding their sign to not get killed?

You’d need some special case, such as, “They came from a SBURB Meteor”, or, “Secondary, Rogue Mother Grub”, or something weird like that. Remember that every single Troll on Alternia, except those made through Ectobiology, come from the same Mother Grub, and there’s Jades taking care of the process, so like… They’d know if a Lime were born. They’d need to be born outside of the Brooding Caverns.