saving onion seeds

So, I am currently growing 2 types of storage onions in NJ(Zone 7). One is a yellow onion(Dorata di Parma) and the other is a red(Ruby red). I want to start saving my own seed and I know that saving your own seed for 2 different varieties of onion in a small garden can cause problems, so I was thinking that I could just alternate years....save yellow this year, save red the next. However, that would mean planting onion seeds that are 2 years old. I know onion seeds are very short lived, so I was wondering if anyone has experience saving their own onion seeds and if planting 2 year old seed is still a viable option

Adam:

I grow my own onion seeds. I have a jar of mixed seed that was harvested between 2010 and 2014. It is currently germinating at about 50%. It has been stored at room temperature. Storing it in the fridge or freezer would have kept the germination rate higher. I live in a very arid climate, and store the seeds in glass canning jars. I think the aridity also helps with seed longevity.

Hybrid onions are male sterile, and thus don't produce pollen, so I only use non-hybrid varieties for seed production on my farm. I checked the variety names you gave, and they are both open pollinated so you should be good.