Mike and Nora, this is what I do:
For the items that are identical except for color, create a complete listing for the first one including the color in the subject line. List it or schedule it for listing.
Go to the saved items list. Your new item is at the top. To the right is a link to create a similar listing. Create a new clone listing from the old one, swap out the picture and the color in the subject line. Ta-da.
If you want to list all the colors at once, go ahead and list or schedule. If you want to list one at a time, then just save the clone listings. When the first one sells, go back to the saved items list and filter for a key word of the item. The original and all clone listings will appear. Because you put the color in the subject line, you can see which is which. You can also see which ones have been listed in the listing column.
I also use folders to sort out listings. I have a folder for partially completed listings when I make listings for things I have ordered but not received yet or have not photographed yet. Then when I list it, I change the folder designation to the listed items folder. The items in each folder are color coded so I can tell which folder any item is in when I look at all saved listings.