Arora Aluminum Color-Changing Tumbler

It's a good thing I did not get these for the "Color Changing" property -- if I had, I'd be disappointed! (I've had color changing cups before that went from purple to yellow and from red to green (the whole cup changed colors) when going from room temperature to cold, so this color change is WAY more subtle than that!). Yes, there is a color change -- in the LETTERING only!When room temperature, you can barely see the snowflakes and lettering (See my pictures), and when you add an ice cold beverage, those snow flakes and letters stand out a bit in a dark blue color. When you put HOT water in the cup, the snowflakes and letters turn to white -- but I do not recommend these tumblers for a hot beverage -- the cup goes to the same temperature as the beverage -- too hot to hold!My guess is that the color change is very much muted by the background color -- the red is too deep of a red to effectively show off the color-changing property! If the tumblers were pale yellow or light blue, the effect would be amplified.So, color-change aside, the aluminum tumblers are just what we wanted -- safe drinking glasses to use at the poolside, won't break when "tumbled", and holding a good amount of liquid refreshment, so there can be lots of ice, AND lots of pop without having to refill every few swallows in the heat of the summer! The only reason they are not dishwasher safe is because the color-change ink could get washed off by hard jets of water, but, in my opinion, I'll still wash them in the dishwasher because if the color-change disappears, it won't be much of a loss, anyway! So, unless you want these SPECIFICALLY because of the color change phenomenon, you'll probably rate these as highly as I am - 5 stars! (If the color change is the attraction, you could be disappointed).