Well, to flip the coin...
I loved the books AND the movies...first-rate in both cases. Although, if I had to choose a "favorite" medium, I'd choose the books. The reason is Tolkien's storytelling. From the Hobbit through the Lord of the Rings trilogy, Tolkien had me spellbound. His incredibly vivid descriptions of various scenes and events often times had me .... closing my eyes and really "seeing" the scene or event in my mind. I honestly and truly felt a part of it. I've never had a feeling like that with anything that I've read, before or since.
The movies, however, are 'any-time' enjoyment for me, as is the music. I'm just sorry that the ride is over. I haven't been as caught up in a story, for a long, long time, as I was with LOTR. Truly, truly magnificent, from the casting to the scenery to the musical score to the f/x. It was a true masterpiece, for me.
* * *
With regards to your question, Mary, if memory serves, the 'gray scenes' were primarily those involving Frodo, Sam, and/or Smeagol. I'm not sure about this - only conjecture - but, the graying may have been done to illustrate the effect of Frodo's burden -- bearing the Ring. (In a rather comical, campy analogy, the effect would be similar to the way the villain's hideaway was tilted, on the old Batman series.)
...and that is my 2 cents.
