I would go for the Green for storage, since speed will not matter.
You always will see some hard drives fail, only some more than others. So I would not distrust "Blue" over "Green", just because one Blue failed on you.
Search Google for WD green drive with words like, "failure rate" "reliability," or "problems." They appear to have a higher failure rate than conventional drives that are otherwise of the same quality. I'll gladly spend the extra power to get more reliable drive.
Also, did you not get a replacement from the dealer or manufacturer right away?
I prefer WD and Seagate drives because they're both top tier manufacturers. Over the years, I've installed them in my own and my friends' machines. I've encountered occasional failures, but both companies have been extremely good about replacements for drives under warranty.
Another plus is that both companies offer free copies of branded versions of Acronis True Image, which allows you to clone the drive. The only restriction on these versions is that at least one drive in the chain (source or target) must be from the company providing the software.
The real bottom line is that any drive is just a machine that CAN fail. ALWAYS back up your data, and if you can afford a second drive, clone your running drive regularly.
For desktops, I like to mount a second drive in a mobile rack so I can unplug it when not in use. There is no virus that can jump the air gap between the machine and an unplugged drive. If your running drive fails, the cloned drive plugs in and runs without having to reinstall your OS and all of your programs. If your running drive becomes hopelessly infected, you can boot to the colone drvie and clone back to the the main drive.
If your running drive is a laptop, you can backup to an external drive. To restore or install the running system on a new drive, start from a recovery CD and clone the image file to the laptop drive without having to reinstall your OS and all of your programs.
Even if your running drive fails or becomes hopelessly infected, once you have a new clone, you may be able to connect the failed/infected drive as a slave, disinfect it (if infected) and try to read and recover any files not on the cloned backup.