Richard,
Canon and Nikon is well known for their excellent color rendering. I think Nikon is great for skin tone, while Canon is great overall, and with its glass/lens portfolio, that's why these two brands dominated the market. It is very easy to tell what scene/photo are shot with Canon vs Sony/Panasonic.
For a while I was trying to match Panasonic to Canon's color, at the end of the day, Panasonic with Scenery color profile and red filter (preferably Magic Filter) will get you very close to Canon's rendition of blue when you do the custom white balance right (with right sun position, water clarity, white/gray slate vs sand/hand). Like Dustin said, Canon have their head in the sand and not giving consumer the right camera at the right price point. They are many times I wanted to switch to the Canon G series for their color, but the video feature just kill those cameras for me. So I switched to Panasonic and spent time to find a way to cope with the color shortcoming.
Sony is very close to Canon's color these days and you can find a lot of video shot with the RX100 with nice blue color, but the WB on the Sony is not easy to work with.
Dustin, Lee tried out the A7S with Shogun, you can check with him how bad it is, and he would rather stick with his 6D, it's that painful!
Moses