This is responding to an old post but I got the same message. I had added orange peel in the fermentable section as a custom so you will want to make sure that your selection is from the drop down. You cant add a custom without a L color. Better to just add it on the right side in custom...

Hello Everybody, I have been brewing for about 2 years and made my share of miss steps but usually I can salvage the, im not so sure about this one. I made my 3rd batch of alcoholic ginger beer, its primarily fruit and ginger root so the addition of sugar is necessary for a good fermentation...