The problems of manufacturing!
Nowadays, all type 3 tips have yellow loops, all type 6 have gray loops and all type 8 have green loops. We used to make type 8 tips with clear loops but that is old hat now.
If in doubt, check the diameter as the thinner the body section of the tip is, the faster it sinks. The type 3 will be thicker than the type 6, which will be thicker than the type 8. That's how we get them to sink at different speeds and weigh the same.
I hope this helps, somewhat!
All the best
Simon