Flex-I-Grit Sanding Film

Anyone familiar with Flex-I-Grit??
I need help identifying the sheets.

A (long) while ago, I bought a package of Flex-I-Grit sanding film,
made by K& Engineering Co. at Micro-Mark.

There are 5 sheets with grits from 23 micron down to .5 micron
(equivalent to 10,000 grit). They are made from silicon carbide,
aluminum oxide, cerium oxide and chromium oxide.

Problem is that I can't figure out which sheet is what grit!

The sheets are black, light gray-beige, beige, dark gray, green.
The package does say 23 ALO and 8 Sil & 23 Sil, so I figure the
Aluminum oxide is 23 micron grit  and the Silicon carbide comes in two
grits.

But I still can't figure out what color is what material is what
fineness.
I think I can tell which is the roughest but cannot grade the others.
(Also, is there a difference in the 23 micron ALO and the 23 micron
Silicon carbide?)

I have a posting from 1996 about using sandpaper in tumblers that
mentions some industrial sandpaper  and give the color coding, but
that doesn't match what I have.

The glass attic page on sanding alludes (I think) to these sanding
films but offers no info on what colors match what size.

BTW, I've searched Web sites - mostly hobby/model shops - that carry
Flex-I-Grit and none that I saw provide this information.
Also, I requested this info from K&S without any response. (I think
they figured that if I can't tell the difference between a sheet of
Aluminum oxide and Cerium Oxide, I'm not worth talking to.)

So... if anyone can help me out on this one, thanks.

--- Irwin

P.S. The sheets are not expensive; it's just that I really want to see
what sanding with the equivalent of 10,000 rit looks like!