Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: I see four pins that are likely: 3.3v, txd, rxd and gnd. Which wire color goes to which pin?
Document: Worked great for me to program Spark Funs Pro Mini Arduinos 5v and 3.3v from Win7.For the 5v version just connect to the programming header.Tx(green) to Rx1 on the Pro Mini, Rx(white) to Tx0 on the Pro Mini.For the 3.3v version omit the VCC/red wire at programming header and power the board separately.Reset the Pro Mini using the boards reset button just as the upload process starts to have a successful upload as has been noted before online.
Works out of the box on Linux (not really surprising). Great value for the money. The individual female headers pins are convenient for boards that don't have the standard 6-pin FTDI layout.
Been experimenting with some serial port (1 wire specifically) hardware and writing my own software for it. I didn't know that the 1 wire devices weren't actually rs232 devices, but ttl. To make a long story short, this device replaces 3 that I had and it gets its' power from the usb port....and passes 5v dc to other devicefs.......My name is George Washington and I approve this message !!! !
Recognized by Linux with no issues.The adapter outputs 5VCC but 3.3V TX/RX. I thought at first this was causing me issues, but it turns out that I forgot to cross the Tx/Rx on the cable with the Tx/Rx on my board (Tx from the adapter goes to Rx on the board, Rx on the adapter goes to Tx on the board). Once I fixed this, the adapter works perfectly to access the serial connection in my ZyXel NSA320 NAS box.
Overall, this is a GOOD product. It works nicely with standard Windows 7 drivers. I'm giving it a 1-star because of poorly attached wires at the pin-connector end - wire sleeve was not crimped to relieve stress. This caused the wire to eventually twist off. It was easily repaired by soldering.
This is a simple FTDI and gets the job done. I'm on Linux (Gentoo), and the module name is pl2303 in case you need to compile it in or as a module. You will see it show up as /dev/ttyUSB, something like &#34;[344919.068686] usb 1-1.1.2.1.3: pl2303 converter now attached to ttyUSB0&#34;
Works great once we figured out which wire is what. Had to go online and check another similar product's description to determine which color wire was what. So yes it meeets the standard, but if you don't know the sandard wiring colors, you need to go looking.
This device installed automatically in Windows 7 Professional and came right up and worked. A wiring diagram would have been nice as I had to come back to Amazon to confirm what wires did what:&#34;four colored-wire : black?GND/ red?VCC /white?RXD /green?TXD&#34;Using it with a custom PIC18 board and it connected right up to the TTL header and starting dumping data to a Windows terminal program as designed.Great tool for the money.
I like that iot is power and console in onecable.See the Adafruit website for wiring.I do not have any dislikes about this product as it just works.
After following the driver instructions and playing, got it working. However, just after a few uses, the connectors have fallen off. They need to strengthen them.I recommend that others use heat shrink tubing when you first get it to see if that helps.
Answer: All previous answers are correct for TxD, RxD and ground.  TxD and RxD operate at 3.3 volts. Paul Hardin is correct that red is 5 volts.  It's a direct passthrough of the 5.0 volts @ 500 ma from the USB connector.