Hey Tim...I don't tie flies, but I tie alot of jigs and am currently working on a number of freshwater shrimp patterns in 1/80 and 1/64 th oz jigheads. Grass shrimp in our regions vary from a light, transluscent beige to a darker light brown color, depending on where you fish.
We use the shrimp mostly in the spring as a tipping bait on small jigs for a variety of panfish. I f you would like I can shoot you a couple of pix
Simple easy pattern
Hook 18 to 10 curved caddis hook
Weight optional small bead head or several wraps of lead wire
Shell back celophane, cling wrap strip 1/4 " wide tied in at back of hook
Monofiliment line 2lb. test line
Gray, olive or white rabbit dubbing dubbed forward
Fold shell back over the top of dubbing tie off in front
Wrap mono over the shell back in even segments
Tim if you will take a look at the shimp they use, you will know color and size
on size 14 thru 10 I like to put 2 or 3 wraps of grizzly hen hackle right at the front.
Wow you fish Okeechobee, oh man one of these days, I am going there!!!!!!!!!