I regularly get drawings from folks in South America that were obviously drawn with a black background in mind. Something that should be boldly visible may be on a yellow layer, etc. I imagine they are just doing black/white prints. But, my company often uses color prints, and this creates problems. E.g. yellow is obviously not a good color for text.
The offending drawings files are, in general, messy in many ways. I wish I could get an hour or so to talk with the draftsmen, to hopefully change their practices. But, in reality, management would probably be the biggest barrier. When you have a large library of blocks that you use regularly, companies don't want to invest all the time necessary to fix a problem that they don't think needs fixing. I have asked my own boss to ask the customer to do the necessary changes, or perhaps charge them for the conversion process, but he is hesitant to hurt the relationship with them.
Fixing layer colors is not that difficult, but blocks and sub-blocks often have entities with the colors explicitly set (i.e. not bylayer). These drawings typically take at least 1/2hr to manually fix. I have found LISP routines that will change blocks to change all the block entities to layer 0 and colors to "by layer", but in my case, it would be best to keep their block entities on the layers they choose. Their entity color should also be maintained, but perhaps just the color itself changed.
Task; Invert the colors so that lighter colors are converted into darker colors. So, a light blue may become a dark blue, etc. Conversely, a dark blue should be changed into light blue.
Change both layer colors, and explicitly colored objects in blocks and sub-blocks.
I am afraid my LISP programming is quite rusty, and don't feel I am up to the task, but perhaps someone will be aware of an existing routine (or set of routines) that can accomplish what I need.
Thank You,
Joe