Why are genes for dark eyes, hair and skin USUALLY dominant but not light genes? What makes...?

That would certainly explain the skin issue. The eye color as brown (or black) would also be more likely the original because it would have contained all the colors. Separation of colors and then loss of some of those colors (green lost one, blue eyes last two) would be a mutation that some now find attractive exactly because they are unusual. For example, in the U.S. now, this is "attractive" because thin is more uncommon and harder to accomplish (you won't go hungry in this country.) 150 years ago, plump was attractive because food was harder to come by and a well-fed woman was attractive: thin was hungry and poor. And that's how opinions work in 3rd world countries.