When enrolling contacts in Playbooks, Playbooks may be one of three different colors:
Red = Scheduled: The Playbook is scheduled to begin engaging in the future.
Yellow = Paused: The Playbook is paused. Nothing will happen unless resumed.
Green = Engaging: The Playbook is engaging and the contact is moving through the playbook.
If the Playbook is Scheduled, it means your Playbook hit its daily enrollment limit and it's now scheduling contacts to be engaged in the future.