I use a tippet dispenser when trout fishing so I really don't have to fuss with various manufacturer's tippet spool bands. HOWEVER, in the situations where I carry spools (warmwater) and on the spools in my tippet dispenser, for decades I've been using
soft, different colored pony tail bands.
First off, the bands hold the tippet material just fine. Then I use the 7 colors of the white light spectrum (ROY G. BIV or Red, Orange, Yellow, Green, Blue, Indigo & Violet) to indicate tippet size with red being the heaviest and violet the lightest.
Even though these pony tail bands don't usually come in all colors of the rainbow, I can still tell what size tippet is on a spool if I know what colors came in the package, what size tippet I usually carry and remember Roy G. Biv. I've been doing this so long that I standardized a few colors.
For example, when trout fishing I usually carry 3X - 8X. Indigo pony bands were always non existent when I first came up with this idea so I just skipped that color. Therefore, 3X is red, 4X is orange, 5X is always yellow, 6X is green, 7X is blue and 8X is violet.
When I warm water fish, I typically carry .013", .012" & 0X - 3X or six sizes. That makes red .013" and violet 3X. I guess if you carry more than 6 spools you could look for other color bands but I have a feeling most people carry less.
BTW - I use this same system to tell me what size tippet is on the end my line when I put away a reel.
I keep one of each color pony tail band in the case for my reel. When I'm done fishing, I wind in the line & leader almost to the end, wrap the last foot or so around the reel foot and secure it with the color pony tail band that matches the tippet size.
The next time I use that reel, if it's a trout reel and there is a orange pony tail band securing the line, I know my tippet is 4X and .012" if it's a warmwater reel.