Might want to consider this Kathy. I like to have my cake and eat it too. :)
I painted my shower skylight white on the roof and it still lets in plenty of light. I guess someone could just paint a portion of the skylight, if they wished.
Then I put some plastic channel in the skylight screws and slid a piece of Styrofoam in the channel to cover the skylight from the inside. I can slide out the Styrofoam and have light or leave it in and take a nap in a dark trailer. :)
The Styrofoam was basically the same material used for making flimsy signs posted on the side of highway on how to get rich. Bought materials at Home Depot for less than $10.
The skylight cover really helps with keeping out the heat and controlling the light in the bedroom. Wife likes the light and I like the dark. It is not uncommon to see the Styrofoam slid half way. We even leave it in during the winter to control the light. :)