You as not addressing his question at all. You are just washing it over with more scientific trivia.
The question is that he noticed a color reflecting off an object of a different color. The answer is that although an object absorbs all other colors it doesn’t completely absorb it. If you overload it with a color you will see that color. Even a black surface will shine with enough light shone on it. Black velvet is an exception, which is why or is used in photography.