Odd camouflage patch from Belgian Brushstroke camouflaged overtrousers.

This swatch of camouflaged material was used to cover the inner seams  of a pair of Belgian camouflaged overtrousers (where the inner leg and front and back seams meet) , it has a pale green base colour with an angular block of brown and faint 'rain drop' like dashes in a grey/green colour. The swatch appeared to have been part of the original manufacture of the overtrousers, which were Belgian 'Brushstroke Pattern', the camouflaged side of the material was faced down so it looked like plain green externally. I believe it is a swatch of German camouflage, presumably from 1956 or before (the overtrousers were manufactured in 1956).