The frame rate of the footage you send to Color must be exactly the same. Color doesn't deal with mixed frame rates. So all the footage, even the slow motion stuff, must be the same...23.98.
What I do for slow motion is first import/convert to ProRes in the frame rate in which it was shot. Then I use Cinema Tools to CONFORM to 24fps. It converts it to 23.98fps. Then import the footage.
Is the footage you conformed NOT 23.98? Again, it must match exactly...the frame rate of all the footage.
Shane
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