Does bleaching remove color from seashells?

I recently went on a Florida vacation and I came home with bags and bags of shells. They smell bad and a lot of them have barnacles on them. I've read that a solution of bleach and water will clean them well, but won't the bleach remove the color? A lot of my shells have bright oranges, reds, and browns. Will the bleach make them just all white? If so, is there a better way to clean the shells that will preserve the color?