Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: In the early 1970s, ABC completed its transition to color; the decade as a whole would mark a turning point for ABC, as it began to pass CBS and NBC in the ratings to become the first place network. It also began to use behavioral and demographic data to better determine what types of sponsors to sell advertising slots to and provide programming that would appeal towards certain audiences. ABC's gains in audience share were greatly helped by the fact that several smaller markets had grown large enough to allow full-time affiliations from all three networks. Question: In what decade did ABC finish transitioning to color?
1970s