Okay, I'm definitely going to make myself sound dumb here... but I'm frustrated.
I'm using Aperture for postprocessing my raw images and I'm going insane trying to figure out how to properly balance color. (I also have CS6 installed, but honestly haven't been brave enough to venture down that path as Aperture's color correction is giving me enough grief.) Until recently, I've been happy with "mostly correct" color (as I'm sure applies to most people!) but I've done some recent stuff where I'd like to get really accurate color, even under less than ideal lighting.
I'm shooting a D7000 with various lenses, and either auto white balance or ExpoDisc corrected white balance.
Here's an example: I have a shot of a white+18%gray+black card. When I auto-adjust on the 18% gray, I get RGBL all set to 125 (as indicated by color values in loupe). However, white ends up at RGBL of 196+191+255+196 and black ends up at RGBL of 25+26+25+26. Needless to say, the image has a blue cast and black is muddy. What is the proper way to get rid of the blue cast without hosing the rest of the colors? When I try to adjust the white to be closer to all 255 (something in the 220s or higher), black becomes gray and the 18% gray develops a yellow cast (as does the rest of the image).
I have an even worse problem when I shoot a color card and try to correct the colors. I can usually get one or two colors close to correct, at the expense of the other colors being way off. It would seem to me that this should be a problem that software should be able to fix without a lot of manual intervention: You shoot the color card, you tell Aperture or Photoshop which vendor's card you just shot, and it should be able to "magically" adjust all the colors for you. I'm obviously not understanding something, but what?
I'm hoping someone can give me some clues as to how to do proper color correction, because I'm obviously missing something!!