You can accomplish the same thing (any color manipulation) with a "tweaked" camera profile. Instead of shooting the color reference chart directly, shoot the reference chart with the film whose "look" you want to emulate, make a print of the film shot of the color chart, shoot the print with your digital camera instead of the original chart and use the film print shot to create the tweaked camera profile. To duplicate the film "look", process the RAW normally, convert to the "tweaked" profile, and then assign your normal editing space.
Suppose you have a digital camera camera that outputs Adobe RGB JPEGs (like the Canon 1D-MkII) and you want to make your JPEGs look like Kodak Portra. Simply follow these steps:
1. Get yourself a camera profiling utility like Eye-One Match and the
Digital Color Checker SG color reference chart to go with it.
2. Shoot the Color Checker SG with a film camera loaded with Portra, and have a life-sized print made using your customary developing and printing process.
3. Shoot the Color Checker SG with the 1D-MkII, and feed the resulting JPEG into Eye-One Match. Save the resulting profile as "1D-MkII".
4. Shoot the Portra print of the Color CHecker SG with your 1D-MkII, and feed the resulting JPEG into Eye-One Match. Save the resulting profile as "Portra".
5. Shoot a subject with the 1D-MkII. Open the JPEG in Photoshop, and convert to 16-bit mode.
6. Assign the profile "1D-MkII" to the image. This will cancel out any color deviations from the camera's internal JPEG processing.
7. Convert the image to the "Portra" profile.
8. Assign the Adobe RGB profile to the image. It will now have the same color characteristics as an image shot with Portra film, minus the grain structure.
I'm not sure why Kodak deserves a patent on this, unless they were involved in inventing profiles and the math involved in converting from RGB to CIE LAB and back.