If you have nice sturdy little plants with three sets of true leaves they are big enough. But you do know they have to be hardened off, right?
Plants grown indoors are very tender, not used to sunlight (way more intense than the lights they've been under), cold, breezes, etc. So you have to get them used to all that gradually a little at a time. Start by putting them out in a protected spot, with no direct sun, for a few hours. Each day you can gradually increase the exposure. Pick your weather for when you first bring them out - windy is at least as damaging as too much sun.
Earlier you said: "There was *one* seedling that the leaves kind of yellowed after being outside. I assume that one got burned from the sunlight?"
Not so. Yellowing is more likely to be over-watering or the soil staying too wet. Sunburned leaves turn white, with thinned, almost crispy spots.
No not "effecting the seedling in any way to where they will be hindered in producing vegetables later on? " Just slowed it down a little getting started.