IS this a simple sentence or compound sentence?

I know that a simple sentence is a sentence with one complete idea and that a compound sentence is a combination of independent clauses where each independent clause delivers a complete idea. How about the following sentences? Are these compound sentences or simple sentences?

Love is like a bullet: It kills everyone on its way.

I have very little time to learn the language: my new job starts in five weeks.

A college degree is still worth something: a recent survey revealed that college graduates earned roughly 60% more than those with only a high school diploma.

All three of their children are involved in the arts: Richard is a sculptor, Diane is a pianist, and Julie is a theater director.

The sentences carry one complete idea; therefore, they are simple sentences. There are two simple sentences; therefore, they are compound sentences.

Which view is right?

Your example Love is like a bullet: It kills everyone on its way has two simple sentences and a colon that is separating the two independent clauses. The second clause expands on the first.

A compound sentence is basically two or more simple sentences joined together by coordinating conjunctions, semicolons, or colons.