Quickest way of retaining display colour of multi object dwg import when allocating to a layer?

Having acquired some Mapping as a dwg file, as soon as I place it to a named layer the yellows and other colours in the map go black, (layer colour default).
rather than have to select each and every different object in the map altering its display to parent rather than layer, if that is the right choice to retain its colours ?.. is there a quick way of doing this.

I did try however one object and despite setting it to display by parent it still goes black !

This though didnt happen to a previous import, came in with lots of layers and I made them sublayers.

this one hasnt such…

correction, I see it has, so by placing such into a new layer the colours are retained :slightly_smiling:

problem solved !

how does one delete a post ? !