Is there any known reason as to why the intro titles to 'Star Trek: The Original Series' changed from yellow to blue after Season 2? It's something that intrigues me perhaps far more than it should. In a show as expensive to make as Star Trek (and where any opportunity to save money would prove most ideal), the decision to ultimately change the titles seems unnecessary.

Not that I'm complaining, I love the variation. It just seems curious that:

A) Such a change was made and that B) They went back to yellow titling for Star Trek: TAS.

If anybody has any information to explain why they made change, I'd certainly be grateful if you shared. It's entirely possible there isn't any reason, but that's not as juicy of an answer.

Season 2 Titles:

Season 3 Titles: