You are in good company, Louis--caddisflies drive most fly fishers crazy. Your post provides a perfect example of one reason for that frustration. The common name problem is bad enough when anglers discuss mayflies; but when the conversation turns to caddisflies, about the only truly common name is Grannom. Everything else is a largely useless mix of "colorful" descriptions. (LaFontaine established a reasonably good set of common names, but few anglers or hatch chart writers use them--perhaps because it requires identification to at least the genus level.)
When I read some "hatch charts," it seems that the primary function is to reinforce knowledge that most fly anglers already possess (like the approximate timing of the well-known mayfly hatches) and to leave them scratching their heads in bewilderment about everything else. And I'm not saying that every shop, guide, or hatch chart author should "key out" every insect on their list or rely exclusively on latinized binomials. But when you read that the "tan caddis" is hatching, what can you do with that information? Not much.
Even though I'm pretty familiar with most of the caddisfly hatches in the Tully (and in PA, generally), the color-coded names don't tell me much either. But, I'll still try to decipher what I can:
Most of the time, "tan" or "yellow" caddis refers to Hydropsyche/Ceratopsyche spp.
Most of the time, little "green" or "emerald" caddis refers to Cheumatopsyche spp. But, it might also refer to Micrasema, especially on streams like the Tully. (Micrasema is a widespread and very underrated little relative of the Grannoms.)
Most of the time, "slate" caddis refers to Psilotreta spp. But, if it is listed as an early hatch (April), it could refer to Apatania--especially if "little" is included in the description. (You can probably eliminate the latter possibility on the Tully. It doesn't strike me as the right kind of stream for them, and I've never encountered them there.)
The "small black" caddis is probably Chimarra aterrima if the body is black; but if the body is green, it could be Cheumatopsyche or Micrasema.
As for the "grey caddis" of the Codorus--beats me. About the only clue I can derive from that description is that there must be a lot of visiting Brits fishing there. :) (Inside joke for the English prof.)
I'm afraid that's about as much clarification as I can offer. Keep in mind, however, that the "uncommon-name-clutter" that contributes to caddisfly confusion shows no sign of abating. I have even seen well-known angling authors using the term "black caddis" as a label for a genus that includes some common species that have nearly white wings and green bodies!!! :(
PS--Be careful when using the body color of "aged" adult Grannoms as a model for pupae or freshly emerged adults. They darken considerably after emerging. The dark grayish-black body of an older or egg-laying adult can can come from a green pupa (usually with a darker back and belly). For example, Schwiebert appears to have made this extrapolation in Nymphs, and many have either followed his lead or made a similar mistake.