I have never seen a photo that shows the individual aircraft letter of an Ar 234 from 1.(F)/100.
There are two in print that I know of:
+GH (white G) at München-Riem at the war’s end (Robert Forsyth "JV 44, The Galland Circus", p. 204)
The wrecked fuselage of +HH (white H) “in southern Germany” (J. R. Smith & E.J. Creek, ("Arado 234 Blitz", p. 189)
Their camouflage looks to be standard, by the way.