If you call $.colorPicker and just alter the sliders it's fine. But the moment you actually use it to sample a value, it then always returns the wrong value.
1. Run attached colorpicker_bug.jsx script. The hex value is sent to $.colorPicker then updated on return.
2. Click Picker and use the picker's sample tool to sample a value from anywhere. For example, the blue from the selected AE toolbar item. Note the hex and RGB values displayed.
3. Close picker and hex will show different returned values. Click Picker again and you'll see how it's altered the RGB values.
Actual result: The blue from selected AE toolbar item is hex 066CE7 or RGB 6/108/231 according to $.colorPicker after sampling, but it then returns b52e1 or RGB 11/82/225.
Expected result: you had one job $.colorPicker!