It took a bit of time but it was inevitable, some manufacturer was bound to add watercooling to their DDR4.  Thermaltake's 32GB DDR4-3200MHz WaterRAM RGB kit incorporates an RGB waterblock which attaches to the top of the DIMMs and can be incorporated into an existing cooling loop.  It certainly does cool the RAM, as KitGuru measured 38.1C without the block, 36.2C by adding the block and below 30C when hooked up to a full watercooling loop. 

As for the effect on performance, check out the full review.

"The important thing here is that you don’t have to replace the heat sinks on the RAM modules with the attendant risk of damaging the ICs, and neither do you have to add a manifold as Thermaltake has done all the engineering for you."

Here are some more Memory articles from around the web:

Memory

• G.SKILL Trident Z Royal 4000 MHz CL17 @ TechPowerUp
• Patriot Viper Steel 4000 MHz DDR4 @ Guru3D
• Team Group T-Force Xcalibur RGB 16GB DDR4-3600MHz @ Kitguru