Although often legal, it's not always the best idea, due to the potential for conflict between deer hunters & small game hunters.
There are ways to reduce this potential, but it's still there, and I say that "sadly" from a perspective of my believing TWRA places too much emphasis on deer hunting while not enough on small-game hunting.
In fact, this is one of my biggest complaints with TWRA's "velvet" deer hunt,
which coincides statewide with the opening weekend of squirrel season.
Some of the better ways of avoiding conflicts include waiting until good light before parking, and not parking anywhere near another vehicle. Most deer hunters will then beat you into the woods, allowing you more opportunity to give them a wide berth. You have just as much "right" to be there hunting squirrels, as they deer, but you may have more opportunity to prevent a conflict than a guy sitting in a treestand.
Even though not required during archery deer segments, I'd highly recommend your wearing an orange hat.
Wearing an orange cap/hat will have little effect on how many squirrels you get.
If that idea others you, consider an orange "camo" cap instead of solid orange.
If muzzleloader or gun season is open, you need an orange vest/coat and hat.
Also, consider there can be a camouflaged hunter sitting high in a tree,
somewhere in the background of those squirrels you're about to shoot.
This is a big concern whether you're that archery deer hunter or that ground-covering squirrel hunter.
I've had some scary moments myself when squirrels were cutting above my head,
then noticed a squirrel hunter slipping my way, getting ready to shoot a squirrel in the same tree I was sitting.