I use anything that is available. Zip-locks, boxes, kitty litter bins, … and now recently, test tubes.
I filled these tubes with stuffs from zip-lock bags.
We can compare the color to the stuff still in bags kept in the dark. That would be interesting to see if the minimal light in my shop causes any color change. Everything is dated and some of the sawdusts are 3 years old now.
You are right, people might think these are the names of people I ground up and the date is when I had a meal. 😂