https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
"ThinkTop Ultra-Light Full Carbon Fiber Bicycle Bike Drink Water Bottle Cage" $28 for two. Weighs less than many carbon cages. A few colors. Available all day on Amazon. Durable, hold 23oz. size bottles of different diameter quite well, easy removal/replacement. They look appropriate on a TCR, Emonda and Roubaix (which all sport them now).
Honestly, these are one of those products that once you find them, you don't bother with other stuff. (caveat: for reasons I cannot fully explain to myself, I put alloy cages on my one MTB).