Here is an email from AAC/A1KKM and I have verified it is on the AF Portal under the AF Uniform Program Page (frequently asked questions) dated 2 Aug
(1931 hrs). Bottom line...you are authorized to wear the new green ABU boots with your utility (any) uniform effective immediately.
 

Additionally, if you are interested in being one of the first to wear the new ABUs, I would highly recommend picking up what you can at MCSS now.  If you wait until formal release, its going to be VERY hard to find anything that you are looking for.

Good Afternoon,

Contacted the AF Uniform Board Branch and confirmed the green ABU boot can be worn with any utility uniform immediately. FYI, either black or ABU foliage green socks can be worn if wearing the green boot with BDUs.

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"Q1. Can we wear the green ABU boot with all Air Force utility uniforms? If so, when?

A1. Yes, you can wear the green ABU boot with all Air Force utility uniforms now. They are available for personal purchase (not issue or unit funded
purchase) in AAFES, Military Clothing Sales Stores. The official authority, via 8106 message, will be forthcoming in late August, early September. The "Safe for Flying" green boot has successfully completed testing and production has begun. We expect to see these on the shelves in early Fall 2007."

"Q2. Why does it appear that there are shade differences with some sets of ABUs?

A2. Some ABUs issued or purchased through AAFES, do appear to have some shade variances, but they are all within the shade tolerance specifications set by the Air Force. This is a normal development process that happens when a new uniform with a new textile is used. We anticipate that this will work itself out as the vendors formalize the process and produce more uniforms.  The different shades variances are authorized."