BloodyHell619
Dithering can happen every frame, but it varies by colour. See the research here GPU Dithering - LEDStrain Forum
The reason is quite intuitive. Let say a device can display light blue and dark blue. If it wanted to display medium blue it could alternate every frame light -> dark -> light -> dark.
But lets say if wanted to display a light-medium blue, then it would be light -> light -> dark -> light -> light -> dark.
If you are seeing the same frequency flicker on every colour you film, its more likely to be LCD inversion than dithering. You can use the colour card in the above post to test this.
EDIT: to add, dithering is usually random, so you should be seeing something like this: 3frames light, 5frames dark, 1frame light, 2frames dark etc