Although the original Tektronix Circuit Computer had relentlessly monochrome scales, a dash of color added a festive holiday look:
Well, OK, that’s excessive.
The intent was to see how the pens behaved, with an eye toward accenting general-purpose circular slide rule scales with a few colored characters.
The green pen shows how I built the arrows by drawing a line through vertical arrow characters:
I like blue ink entirely too much, having used a blue pen as my daily writer for most of my adult life:
Red ink for “backwards” scales and suchlike would work well, even if it’s too vivid for the tick marks:
Those are all on unlaminated plain paper, with plenty of room for improvement.
Seeing as how I’d be doing all the “tool changes” manually, optimizing the plotting sequence would be mandatory: one pen change per color per deck!