To get a better idea of how a selection is in the Color Range menu. you can switch views
Tick either one of the two options Selection or Image at the base of the Color Range menu.
To view the area that you have selected, stick to Selection view which should be the default.
For a better idea of the colours that appear in your shot switch to the Image view.
This is especially useful to see what colour values are present across the image before committing to any of selection.