You make a good point about the '50th Jubilee' decal which was teal-colored. And since it was still officially a Model 1205 (service manuals tacked on a 'J' to make a distinction between the teal 1205s and the gold) it likely retained the teal cord on the PN-2 and some of the attachments. Another possibility is that teal-colored overstock was used on the early Jubilees and later ones were furnished with the new ivory color items. The ones I have seen for the Jubilees, Super Js, and Olympia Ones have ivory tools with no secondary color--except for the brush plates that were painted the same as the tank bodies (which had been done since the tool was introduced on the Model E in 1954).
Along with the teal accessories you mentioned I wanted to also mention that the hoses for the Jubilee and gold Model L of the same period were snow white with triple teal/gold/teal tracers. These were also used on the early Super Js. However, the later gold Super J and gold Model L hoses had triple teal/white/teal tracers.
In fact, beginning with the Model F in 1957 teal was used as a tracer color--even though there was no other teal on the tank like the Super Js and gold Model Ls. Ditto for the drop-down Model R. Then came the aqua Model G and ivory Model L turquoise hose with double teal/white tracers, but the teal matched the trim on the tanks. So there doesn't seem to be a consistent reason teal was used in hose tracers other than it was an attractive and complementary color.