Sean:

Amazing photos!  I recommend you submit a report and photo of the band to 
the USGS bird banding lab at Patuxent Research Refuge.  They are at:  
http://www.pwrc.usgs.gov/bbl/homepage/call800.htm

For the metal leg band you would normally need all the numbers, but the 
colored one/s is unusual and since you got a great photo they may be able to 
id it as a result.

There are specific color codes and number/letter combinations.  You can read 
more about color bands used specifically for Peregrines at: 
http://www.pwrc.usgs.gov/BBL/homepage/pefaprot.htm

Cheers!
Jeff Shenot
Croom MD