What is it about an index?

Is it just me? I never seem to be very happy with the indexes in my books. I guess it's the control freak in me that balks at the requirement that the publisher hire an index specialist. The only book I did the complete index on was the original Exploring Color, before the requirement was put in the boiler-plate contract. Indexing was one of the hardest things I've ever done. I completely redid the next two indexes after publication, they were so unsatisfactory. With the fourth and fifth books I had the opportunity to review the index before the books went to the printer. One of them was dreadful, the other not so bad. This time I didn't review the index, and while it isn't awful, I just don't get what causes indexers to note a word in one place and ignore it in another. I'm honestly trying not to be too picky, because I hate bloated indexes more than over-simplified ones. I do think an index is useful and essential in the kinds of books I write. Proofing an index is almost as hard as making one, I think, but I imagine indexers wouldn't agree with me on that.

The new book is fantastic. I'm astonished at the color. It's hard to match printed color to original art, but when I showed one artist his painting in the book, we compared it to the original and the color was dead-on. That pleased me no end.