Agreed with above comments.
Realize the cutters were improvised from beach anti-tank barricades. These sat in the water & sand exposed to the elements and would be a dark rust color. Torch cuts make a edge with fine lines that are dull silver to a almost white border. This white is not in the metal and will wipe off with a rag or glove, like a 'smoke' residue.
Assembling the cutters involved welding and grinding which would make a bright silver 'polished' area usually where the weld needs to bond or in molten metal 'fuse' I do not think they bothered cleaning up the slag or applied paint, all recent welding would oxidize or rust quickly to a brighter orange almost over night.
These were a make shift measure that was campaign specific to be disguarded after the hedgerows were a memory not a concern.