This is SUCH a good idea!
Schmetz needles are now color-coded. I can't tell you how many times I've had to hunt down my magnifying glass to see what size needle I stuck in my pin cushion. I started pinning them to Post-It notes with the size and history: "#90 used once, maybe twice, either on clothesline bowl or to poke holes in garden hose."
I might have known the size, but I could never tell what kind of needle I had! Now? Problem Solved! From Universal (no top band) to Topstitch (pale turquoise) to Microtex (purple) all I have to do is look on the needle.
Head over to the "All About Needles" page on the SchmetzNeedles.com web site for some awesome (and entertaining) information about needles. This is an important topic too many of us know too little about---me included.