First and foremost, you must setup your camera correctly. We have found a way to do this with the Sony to shoot in SLog but still have access to ISO 200. The True Color Pro ALPHA LUT is based on using this setup and will produce magical results as you can see from the before / after video here.
We did not invent this camera setup and it is actually from Matt Johnson (with thanks to Marien also the original creator). To setup your camera properly and ready to shoot easily gradable footage, follow this video :