Is it possible to change the color for quick picker selected option via settings?
There are 2 variables that I know of associated with Quick Picker. Neither seem related to a hover color but they may be. The 2 are:
pickerGroup.border: Quick picker (Quick Open) color for grouping borders.
pickerGroup.foreground: Quick picker (Quick Open) color for grouping labels.
Hope one of these helps you. Try them in the settings file.