For some time now, I’m facing weird behavior of Corona Color Picker when setting values, with Corona v1.7.2 and 3dsmax 2018.4. Please check this video capture: https://screencast-o-matic.com/watch/cFniDRopAk
Really annoying … any idea please ?
As to colors close to 0 being transformed into 0 - see reply by Romullus above.
As to some color values not being applied at all - try selecting the color you need, then clicking anywhere inside the color picker ui with your mouse button, and only then clicking ok. Does it work then?