PLT is HPGL which is a Plotter file.
So if you can import PLT with full color then your choice is endless.
What you need is ABViewer or any DXF to PLT converters (ACME CAD Converter for ex.). It's allows to convert anything to PLT.
You can take a DXF format and convert it to PLT. There are may free software to create DXF. Blender for 3D. Inkscape for 2D. As far as I know almost all vector drawing programs can export to DXF. Also Anarchy Editor does read DXF files. Check if you CAN import color PLT. And if you can. You can do whatever you want. There are tons of products.
I hired an Italian guy to do my wires. Now they look like spaghetti!