http://www.tioh.hqda.pentagon.mil/FlashTrim/509InfantryRegiment1BattalionFlashTrim.htm

With the activation of the 3rd Battalion the Army had approved a flash and oval in a slightly different color border:

http://www.tioh.hqda.pentagon.mil/FlashTrim/509InfantryRegiment3BattalionFlashTrim.htm

This means that the 509th is the only regiment I am aware of with each battalion having a different color for its flash and oval.(the 2nd Battalion was the inverse of the original 1st Battalion, and the PIB was different than all three)

The Regimental and original 1st Battalion flash and oval:

http://www.tioh.hqda.pentagon.mil/FlashTrim/509InfantryRegimentFlashTrim.htm

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