15 The Son is the image of the invisible God, the firstborn over all creation. 16 For in him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and for him. 17He is before all things, and in him all things hold together.
The word "all" appears 5 times in these 2 verses. The phrase "in him" appears twice.
Paul depicts a unifying and universal framework in which all created things exist. All normal matter, dark matter, and dark energy exist in this universal framework.
Is there anything outside of this framework?
No, except the uncreated God himself.
1 John 1:
5 God is light, and in him is no darkness at all.
This metaphor refers to God as a person, not as the universal framework. God is a moral agent as a person.
How can all things hold together "in" him1 if there is no darkness "in" him2?
him1 refers to the universal framework; him2 refers to the moral agent of God.