How to clean old white silk shirt ?

Question:I've been washing my silk shirt that i had made in China for years with no problem and now I made mistake and washed in a load of dark clothing.
Now my shirt looks dull white and I'm in need of some suggestions please.

Answers:
Soak it for 2 to 3 hours in solution of 1 gallon warm water and 2 ounces of 3 percent hydrogen peroxide, in the sink or a plastic (not Metal) container. After soaking, rinse the blouse thoroughly in warm water and dry it on a hanger--for best results, in a room without sunlight.