Hi, Gents
The photo of LT Brown that I have (and uploaded) is B&W. I will venture some guesses based on personal snaps of the time...not to be taken as binding.
The pocket patch was locally made. As Brown was a Scout pilot, I propose that the background of this to be white. Here is my reasoning: air cav troops had four platoons - HQ (mess, admin, etc) and three flying platoons of Red, White and Blue. The "Blues" were the air mobile rifle platoon (Blue being the formal uniform branch color of the infantry) and the associated UH1 lift birds. Red was the color of artillery branch and the organic gunships were our in house firepower so the guns platoon were "Red." These were almost always AH-1G by 1970. By process of elimination, the Scouts were the "White" platoon. In 1/9 Cav Scouts flew the Hughes OH6, in 3/17 they had OH58 as I recall.
A scout plus supporting gunship was a "Pink Team." But, Brown was a White.
The scarf could be any color - yellow would set off the piece nicely, but it could be an OD cravat (medical bandage cloth) frequently worn to ward off dust and to mop sweat.
His uniform could be jungle fatigues, but as there are no pleats on the pocket I would guess it to be the drab brown Nomex flight suit shirt.
Hope my guesses help. Ask if more are useful to anyone.
NR