I mean publicly America hasn't made an effort to really "colonize" any country per say and Imperialism has ended.
However, and I'm entering conspiracy theory territory here, that's not to say America doesn't have 'colonies' around the world today.
America has countless treaties with other coutnries that favor them. These treaties basically give America unlimited access to certain countries and regions.
I'm gonna talk about 3 ways america spreads its influence in a non-chalant way in the modern day.
1. Capitalism. Remember the cold war? Remember containment? Remember how Russia and America were both competing on who can turn the most countries capitalist/communist. Yeah, America is still using Capitalism to control countries today. I'm not gonna go too in-depth about this, just please watch this video, it's very insightful.
2. Militarism. America has military bases in countries all over the world. These countries range from Saudi Arabia to most of Europe. In some cases, America has full access to a country's military. You can look up statistics about american military bases and you'll get the idea.
3. The U.N and the Security Council. I might be alone in thinking this but the U.N is basically just another way for America to flex its muscles. The U.N is literally America's puppet. America contributes to the U.N's budget more than any country in the world. Through the U.N, America has bailed Israel out of its war crimes and just did a whole bunch of shit( through veto and what not) to its own advantage.
Now all 3 of these resemble Imperialism pretty closely. In other words, America has successfully 'colonized' a lot of the world today.