There are almost as many CAD standards as there are cads. While it is common to associate color with lineweight is not necessary to do so. You can set lineweights by layer, then set you ctb file to plot linesweights by entity.
Before plotters and CAD draftsman used technical pens of various line thicknesses. They came in sets with a good and pleasing proportion of lineweights. Sets with 0.18, 0.25, 0.35, 0.35, 0.50, 0.70 pens were a common combination. 0.18 is very thin and may not reproduce well, so I use it only very rarely. 0.50 is a medium heavy line. I might use that for right of way line or similar. Something heavier yet (.070) for the external boundary of the project parcel. Lighter weights (0.25, 0.35) for interior boundary lines. The 0.25 weight for easement lines.
Leroy fonts are lineweight dependent. Truetype fonts plot the same regardless of lineweight or pen settings.