Been a long time since I dealt with those old school brass radiators. That being said, in today's world of plastic tanks/aluminum cores vs all aluminum. I'll take the plastic tank/alum core all day long.
Colors are mostly for making the chart easier to visually follow the routing, though some factory hoses may be marked with the corresponding colors via a stripe on the hose. I venture to guess the solid colors are constant vacuum and broken colors are "triggered vacuum" or "off idle" vacuum from...
I have had this one for quite a while, pretty happy with it. I like the portability of it.
https://www.homedepot.com/p/RIDGID-4-5-Gallon-5-0-Peak-HP-ProPack-Wet-Dry-Shop-Vacuum-with-Fine-Dust-Filter-Expandable-Locking-Hose-and-Accessories-WD4522/100638389