This is an issue that comes up again and again, yet again and again, I see that folks are missing this important part of the craft of digital photography. If you consistently want the best color in your images, I suggest you never use auto white balance outdoors and use a specific white balance instead. I have heard it all -- so many folks say that it is so easy to change white balance in RAW, that you can simply set your camera to AWB when you shoot RAW and set white balance in Lightroom or other program. While that is true in the abstract, it doesn't seem to work in real world photography for most people because I consistently see problems with white balance due to problems with auto white balance or AWB.
First off, AWB is inconsistent. You can take a picture of the same scene with wide angle and telephoto focal lengths and get two different white balances. The colors will be different, even though they should be identical. Now you are faced with a workflow problem — you have to adjust white balance of at least one of the photos, yet if you set your camera to a specific white balance, often you would not do any adjusting at all.
Now if you have to adjust white balance, then you are faced with a decision. Suppose you have those two images that came up with different color because of AWB — which one is correct or alternately which one is better? Or maybe neither! So regardless of what program you are working with, you have a workflow issue where you have to go in and change white balance settings.
And that gives another problem. A lot of people see the settings for white balance in Lightroom and Camera Raw, notice that they are similar to the camera’s settings, and figure that they can just set these settings there. Actually, you can’t. Those settings are Adobe colors, Adobe interpretations of digital image files, not interpretations of a real-world scene as your camera is doing. This means that if you have two radically different images that are both in standard daylight conditions and set both to Adobe’s daylight setting, for example, you can get different looks for both photos. That’s definitely a problem.
And there are other problems, such as sunrise and sunset. In those conditions, you want a "color cast" because that is what is normal. AWB doesn't know that and will try to remove some of that color cast, exactly the wrong thing to do, so you end up with less than the best color for those conditions.
Another problem is one that I had not thought about until I started seeing so many photographs from my students at BetterPhoto.com that I could recognize as having been shot with AWB. When digital cameras first came out, I was an advocate for setting a specific white balance, especially when shooting outdoors. This, to me, was simply a part of the craft of photography now modified by digital. I have always felt that it is best to capture the best image from the start rather than trying to “fix” it later, which is what using AWB plus a RAW software to set white balance does. But I did not believe that I could actually recognize AWB until I started seeing consistent color problems such as weaker colors and colors that are contaminated by blue.
What I think seems to happen is that the photographer gets back in front of the computer after shooting something outside and sees the image in isolation. AWB may often give a compromised color, but it usually looks “okay” on the monitor, and most photographers don’t shoot a series of varied shots of the same subject, so they don’t see the variation in color that AWB gives. So they don’t make the white balance adjustment needed, the white balance adjustment that some RAW aficionados say makes AWB fine to use. AWB would be okay to use if the photographer always made an adjustment, but so often, like I said, the AWB photo looks okay and so the photographer accepts the weaker color and contaminated blues because there is nothing to compare to.
So for me, it is a workflow and photographic craft issue. I set my white balance to a specific setting because I want consistent results when shooting in the field, because I want to be sure I have captured the best colors while I am still in the field, and because I don’t want to have to “fix it” in Lightroom (which is my program of choice).
Do I use AWB? Yes. I think it is an important control when you are indoors with screwy lighting. It can be hard in those conditions to figure out what to do for white balance. I also think that custom white balance is a good thing to use in those conditions, including devices such as the Spyder Cube that are a great help when working with a RAW file in Lightroom or other program in order to get neutral colored neutral colors. Custom white balance is trickier to use outdoors in nature because there are often important natural color casts to such scenes that you want to retain or even emphasize.