Why would you call colocation "building your own data center"? You could call it "colocation" or "renting space in a data center". What are you building? You're racking. Can you say what you mean?
Come to my office and tell me how it’s not actually my office because it’s leased by my company from the investment vehicle for institutional investors that owns the building that stands on land owned by someone else again that was stolen by the British anyway and therefore calling it “my office” makes me a fool and a liar and I should just “say what I mean”.
But if I said I’m building an office, would you assume I’m furnishing an empty rented space, or constructing the building?