Apple has released a pretty important EFI firmware update for mid 2012 Macbook Airs. It fixes a color issue with external HDMI displays, and also solves problems relating to Windows (surprise, suprise) and Thunderbolt.
![macbook air efi update](http://www.mactrast.com/wp-content/uploads/2013/01/macbook-air-efi-update-582x121.png)
It only weighs in at 4.76MB and requires 10.8.2
You can download it via Apple’s website here or via Software Update on your Macbook Air.
From the download page:
This update fixes a color issue with HDMI displays connected to MacBook Air, resolves an issue with Windows which can prevent MacBook Air from booting properly, and also resolves an issue where unplugging a Thunderbolt device may cause the system to freeze when waking from standby.