im new to the board and id like to share this FCPX effect which i find quite useful when color grading directly in FCPX.
Sometimes in CC you want to drag the shadows to a strong blue or green tone (or anything else).
Problem is that coloured shadows look somewhat unnatural. The integrated color board delivers saturation controls but they are too widespread over the values and offer no fine control.
With this effect you can define the range, curve and soft or hardness of the selected matte and desaturate a specific range of shadows. Try it out and you´ll know what i mean. Below some notes on usage and a download link.
You should immediately notice the effect when you apply it. However, if you use it on clips with low saturation, it might be hard to notice.
Try the following: Apply a strong look to your clip with a LUT or Color Correction and then apply the effect. You should see that Shadows get desaturated and with the sliders you can very accurately define which and how much shadows will desaturate. Problem is that you usually do this with a nice Luma vs. Saturation curve. Sliders are a bit complicated for that purpose, but when you get used to it, it works. I actually use it quite often.