I lived in Hawaii when Apollo 15 returned from the moon. I saw the crew return by helicopter from the ship to Hickham A.F.B. and when the helicopter carrier, the USS Okinawa (LPH 3), returned to Pearl Harbor, my father (a USAF full-bird colonel) arranged for my family to get a tour of the ship from one of the frogmen who helped keep the command module afloat and pull out the astronauts. He gave me a small piece of the gold-colored mylar foil which he said he and other sailors stripped off the outside of the command module as souveniers (I saw the capsule on the hanger deck). The sailor, I saw, had retained about a piece of foil about 9 inches in diameter.
The capsule did look clean as I saw it on the hanger deck, not like this photograph of Apollo 11 as it was hoisted onboard the Hornet; rather it looked more like the cleaned-up version of Apollo 11 in the Air and Space Museum. I suspect that the mylar foil was on the underside of white paint that burned off during reentry, and that the sailors finished the job. But I do not know this.
Is this piece of mylar I have MLI? Is it possible to have that verified? If it is MLI, what material would have covered it so that it did not look gold on liftoff? Was it always that color, or did its color change? Is it worth anything today?