Here are some random shots taken with the 1dm4.

I'm trying hard to use the LCD under the available light and Kelvin to change the color of the skin to try and get something good to work with. Just wondering how people are able to maintain the same skin tone throughout several shoots?

Friends Contagious on Vimeo

Are you using a Vari-ND filter? I'm just curious cause it looks like you are wrestling with lighting levels.

I would suggest just doing a standard custom WB on the camera. Leave the Kelvin settings alone. This should help keep your colors consistent. Also film the grey/white card you use so you can tweak in post.

I really like your video. I do have a suggestion though. It would be cool to hear some of the kids voices. I don't know if you captured that or the background sound is too much. IMO, it would be cool to have a slightly muted 2nd layer of audio. Just an idea.

All the shots were taking inside under lighting that was just enough or too little. No vari-ND filter used. Using a custom white balance every time I break it out for a little video here and a little video there seems too much for what I'm currently doing, which is getting use to the NLE etc. I will make the effort to try and use my grey cards. I haven't needed them for a long time. I usually tweak my RAW still shots in Lightroom so AWB is all I need. I wish video were the same.

Once Magic Lantern is available for the new firmware, you might give zebras a try. The latest Marshall HDMI monitor has false colors, so that's another option.

With ML, I would set the skin tones at 0xb000 or a bit lower. You can also check if your highlights are blowing out above 0xf000. If so, add more fill light or use a reflector. We often color balance with an ExpoDisc. Using these techniques, one can get consistent skin tones.

There is also a WB Offset in the menus. If you find that you don't like the skintones on a clean exposure and color balance, you can apply a slight offset to get just what you want.