In 4.0 alpha and beta versions, changing the saturation or lightness in the color window seems to update the RGB, and then get a new HSV from that. I made a video to demonstrate this and how it becomes annoying:
Note in previous versions (shown first), changing the saturation would keep the hue and lightness the same, as it should do, whereas now it seems to change them, losing your original color. This is pretty frustrating when working with HSV, as just wobbling the slider a bit without releasing your mouse will lose the color you're working with, and making a color darker then lighter again will end you up with a completely different color.
This is especially annoying when you're changing the lightness of a color back and forth a lot, even more so if you haven't yet drawn with the original color you picked out. For example when you pick a color for an object, make it lighter to draw some highlights, make it darker to draw a shadowed area, and then suddenly your aqua blue has turned into an ugly burgundy.
