Good news, Canon just announced yet another firmware update only days after their last one!
Firmware Version 1.1.3 incorporates the following improvements and fixes.
1. Fixes a phenomenon where being in the proximity of the camera and an Internet-enabled device may cause the user to complain.
2. Fixes an Internet phenomenon where exposure metering may change when using the top LCD light in underground crypts or tombs. Under these circumstances, the camera will now simply play a sad violin song through the monaural speaker and shut off for 3 minutes.
3. Reduces the Nikon D800's DxO score to 62.
4. All picture profiles are fully updated and now personally approved by Ken Rockwell for their increased vividness.
5. New interactive menu screen that lets you choose why you are returning your camera before shipping it back to us.
Thanks to all that are trying to help with this.
Snarky comments like the one here are pointless and make me think that those people don't own either of the cameras I am talking about.
Again thank you all who have had sincere and helpful answers and opinions so far.
Sorry, I felt that you were already presented with enough information to either tweak or return your camera by that point. I had already responded with my thoughts. I viewed your comparisons on 2 calibrated IPS monitors and I saw yellow shifts on the 5d2 and a magenta shift on the first 5d3 sample. Neither camera was perfectly neutral, but I definitely found the 5d3 to have done a better job on the outdoor picture, mainly because of less harsh highlights on the dog bone and the lack of the 5d2's yellow cast.
This is definitely a case of adjusting your workflow or equipment, as a new camera with new RAW decoders in Lightroom is never going to perfectly calibrate to your old camera.
I shot with the 5d2 from the week it was released and upgraded to the 5d3 on day 1. I shoot food photography for a living, which is highly color sensitive. Color-wise, I'm seeing a huge improvement in reds and oranges. I shot a whole cookbook for citrus on the 5d2 and I wanted to jump off a bridge because the camera would just blow out the color orange until it was simply a single-toned blob.