When I use my S700 to shoot slomo (usually at 240fps) the colors are much different and less natural then when shooting at normal frame rates. What causes this change in color tones?

I've shot a ton of slow motion and have never noticed any change in color tone from normal frame rates, only exposure changes as you would expect.

I wouldn't say I have had different colors shooting HFR but I have had decreased DR when shooting HFR. The highlight edges look funky imo at 240fps. I just shoot 120fps when needed for now till I can get the camera in for the firmware upgrade for S-Log2

My camera displays what I would call a slight but obvious white balance shift between SSM and standard frame rates. In high key scenes, it's not detectable. In low key scenes with a dark background, there is a slight but noticeable magenta cast in the whole image, but most noticeable in a dark mono-tone background.

Where this really shows up is filming something like a dance recital, dancer in light colors against a dark backdrop. After putting normal frame rate footage and SSM footage together on an editing timeline and playing through, the transition from normal frame rate to SSM is very, very obvious, with the background toggling to magenta cast after going to the SSM cut.

No idea why it happens though. Annoying, yep, you betcha...