There are 2 different yellow hypalon colours that we stock at RIBstore: Colorado Yellow and Sunflower Yellow.
Thankfully they are quite distinguishable from each other - Colorado Yellow is a more traditional yellow, where as Sunflower Yellow has an orangey tinge.
If you're familiar with the Camel Trophy Ribtec RIBs, these had Sunflower Yellow tubes.
This comparison photo should also help you confirm which colour hypalon tubes you have: the black handle is fitted on a Colorado Yellow tube and the sheet of fabric is Sunflower Yellow.