Ideas for lightening up a fish?

Hey everyone, I just finished painting a walleye for a friend. It was caught in lake winipeg and had a lighter green tone to it. After finishing it up and glossing it, it turned out darker than I wanted. Im happy with the painting other than I wish it was a few shades lighter. Is there anything I could do to lighten it up now? I know what I'd do different now, I just don't really want to strip it and start over. Any ideas are appreciated. Thanks. I'd post a pic but Just got a new computer and haven't had a chance to get my camera hooked up yet.

 

Thanks guys. Thats what I kinda figured I'd have to do. I was just feelin lazy and hopin there was an easier, quicker way. thanks again.