Apple Motion 5.1.3 and FCPX 10.2.1 crash when using CMYK slider in Color Picker

I have a precise color I need to use and the reference is in CMYK.
I am able to switch the Colors selector from RGB Sliders to CMYK Sliders, but when I try to adjust a slider, Motion crashes, FCPX as well.

Are you too experiencing this? Obviously others do:
https://discussions.apple.com/thread/7031542
https://discussions.apple.com/message/28249186#28249186

Update:
I thought I could workaround this bug by doing this:
Open Textedit, select Format / Font / Show Colors.
That will open the Color Picker floating window identical in all Apps including Motion and FCPX.
Go to CMYK Sliders, and create your colors without crashing, save them in the color swatches (buckets).  Then go back to Motion, FCPX - the colors are there in their buckets, ready to use.
Except that when I pick one of these newly created color swatch, Motion CRASHES.
So no luck...

But then, I had this idea:
Open Textedit, select Format / Font / Show Colors.
That will open the Colors floating window identical in all Apps including Motion and FCPX.
Go to CMYK Sliders, and create your colors without crashing, SWITCH the slider to RGB slider, THEN save your color in the color swatches.  Go back to Motion, FCPX - the colors are there in their buckets, ready to use.
This time, no crash! But, come on Apple, can you fix this please.
From there You can create a new Palette and save and organize your new colors.
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PS: I can't find a way to "erase" a color swatch (bucket). It seems the only thing one can do is replace a color with another, but no way to drag out a color to empty the swatch. Has someone found a way? Let me know.
PS update: Drag a color swatch to another and that'll empty it. So basically all buckets can be erased but one.

Update:
Apple has corrected this bug in FCPX v10.2.2. Thanks!