Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: ? are these retro aluminum tumblers and Pitcher dishwasher safe?
Document: These retro aluminum tumblers are so fun! The neighborhood kids all love them and the colors are fantastic. That said, you will get sick of hand washing them and inevitably put them in the dishwasher -- once you do their color is not long for this world! So I just ordered more!! They are too fun to pass up, go for it!
A poor imitation of a classic product. Shoddy workmanship, especially on the pitcher. I could not in good conscience recommend this product to anyone.
nice color.. just what we wanted. colors were good it was what we wanted, we do like these tumblers. very nice
These tumblers are great! However, the coloring begins to fade with the first hand washing and even gets wiped off if you dry them (tried a dish towel and even a simple paper towel).
Oh, those wonderful backyard picnics. Gulping ice-cold Kool-aid from those glistening cups. I'm really going to enjoy these now, poolside, sipping iced tea while lounging under tall cottonwoods. Thanks for making these available.
I ordered these primarily because I have kids and glass doesn't always stay in once piece. We love them so much I'm about to order another set of 16 oz glasses. Super strong, hard to dent, even harder to scratch. Highly recommend to everyone.
I bought this item for my nephew for x-mass and he really like them.I grew up using this type of cup at grandpas house and thought hewould like them and he does.
Answer: They lose their shine.