Don't hesitate to pick up and use markers both before and after finished. Pantone or any other permanent waterproof marker will do. You can buy grizzly/white hackle and make it whatever you need.
I haven't had issues with whitings twisting. The size issue is something you need to consider. But on a side note, some dries us smaller or larger flies than what would be considered standard. take an Troth style caddis. You can either use a full hackle for the size hook and trim the bottom, or use a smaller hackle and achieve the same thing. Henryville special caddis would be along the same lines. Al's Trico you can trim the bottom to sit flush. A simple spent caddis uses dubbing for a body, a mottled feather (patridge/grouse) for a over wing, and a hackle over peacock head. trim top and bottom for a spent fly.
Another fun part with hackle is you can trim them flush. turn a full dry into a sort of emerger that lays in the film like the spent caddis pattern I just referenced. Or the bottom on the Al's Trico. You can do this with any pattern and may find they work better than full on adult.
Do you tie emergers? they're much more productive! They're easier to tie general, and use many of the materials it sounds like you already have. Dubbing, some ribbing and deer hair, or thread, ribbing and deer hair, or cdc, Foam, or marabou for wing, peacock for an abdomen, thread or dubbing for a body. Google midge emergers (serendipity). Grease your leader and use the appropriate floatant for the wing and you're set (powder for cdc, I prefer paste for the rest).
I'd 2nd parachutes are not hard. I also believe they catch more fish. Your comparaduns should do well. Use a post material that you get ahold of (antron, zlon, calf tail, krystal flash, etc). the posts are more for you to see, than what the fish want. Color your white/grizzly hackle a dun, brown, etc to match what you want to tie. remember flies are a suggestion until you cross over into realistic.
If you have some materials already you likely can with a little ingenuity or home work cross over. Like using antron/kflash for a tail instead of biots, fibers, or hackle. The antron and krystal flash would insinuate a trailing shuck of a cripple or emerging stage closer to being a full adult.
I'm usually hesitant to post on threads like these.....as you'll find out there are many ways to skin this cat. Only you can decide what you're approach is going to be. getting as close to a recipe is a great place to start...if you're missing something use your imagination to replace it, or leave it out. I leave out wings in drys out of sheer laziness from time to time and still catch fish. Or tails in parachutes and they produce just fine. sometimes thinking outside the box is the difference between a skunk and fish!
Welcome to the wonderful world of tying!