Star Trek

I would like someone with a really solid working knowledge of the original show to help me with this small problem. I am watching the original series on Hulu and the opening theme is an operatic singer with yellow titles and credits. I could swear that for most of my life, the original theme was a blended operatic singer and blue titles. I've read that the blended/sci fi style theme was only used in the last season. However, the Hulu series is using the operatic version in all the seasons as far as I can tell. Could someone please tell me what and when these two different versions aired and when the titles changed from blue to yellow? Is that just recent? Also, are all the original series on DVD now containing all the updated graphics of planets etc? Do you get the original versions as well if you buy the DVD's (I mean with the original backgrounds, planet graphics etc.). Thank you.

You can try to look it up on Memory Alpha. There is also another very helpful and useful site. Just google Trek Core. On both pages there's a load of information regarding DVD releases, credits, graphics and stuff like that

If I remember correctly, the 1st season had instrumental music, with yellow letters. The second season introduced the opera singer, but still had yellow letters. The third season had the opera lady and blue letters. I don't know what hulu has, but it would be strange to have something different.