The short answer is yes, it can be done. The best way to do it is by putting the saddle into a large glass jar that is filled with Hydrogen Peroxide. Use the Peroxide you can buy at any grocery store of pharmacy. Put enough peroxide in the jar so that the saddle is immersed in it, and set it aside overnight. the next morning check to see if enough of the color has been removed from the saddle, if so, take the saddle out of the jar. If not, let it sit at check it every 3 or 4 hours. Once you get the lighter color you are looking for, rinse the saddle in a weak white vinegar and water solution and follow this with a thorough rinsing in clean, cold water from you tap. Squeeze the excess water out of the saddle and place it between 2 sections of newspaper, press the newspaper with your hands down on the saddle, repeat the newspaper pressing with dry sections of newspaper, and then set the saddle aside with the skin side down on still more dry newspaper to dry at room temperature.
Do not use bleach, as it will ruin the feathers!!!!
And the straight low concentration perozide from the drugstore of grocery store will prevent you from lightening the color too much.