No expert here,but I did read this:
"A radome with an excessive amount of filler and/or multiple coats of paint will experience loss of efficiency. Too thick of a coating can reduce the transmissivity of a 90 percent radome down to 50 to 60 percent. When refinishing is required, it is essential to remove all old paint and evaluate previous repairs."
so maybe it was to much work to put on the proper color camo from the Vietnam era