I’d like to say that I’ve had a very positive experience with the RGB backlit LCD.
I have incorporated it into an Arduino-based dual-stage temperature controller that keeps a refrigerator at whatever temperature I set it with a front-panel switch (used for brewing beer). When the temperature is within 1 degree of the setpoint, the display is green. When it turns on the 110VAC to the cooling outlet (fridge power), it turns the display blue, and when it turns on the heating outlet (40W light bulb), it turns the display red.
It’s a great application for that display and has impressed a few people. I’d be willing to share some pictures if you’re interested. It uses three of your TMP36 sensors and an Uno.
p.s. It also incorporates an XBee so I can control the temperatures remotely (it’s in another building), but I can receive ambient air, ambient fridge air, and carboy temperatures for logging. Remote control is handy because of the temperature fluctuations required for lagering that take place over the course of days. Might as well automate that instead of walking out and manually changing the setpoints, right? 🙂