Sanibel Island FL - buff-colored sparrow-ish? (1 Viewer)

I know this is a long shot and I hate that I can't offer a photo.
Yesterday at the Bailey Track, I caught a glimpse of a sparrow-sized bird. It had a sparrow-ish type beak and (in the brief moment I had to view it) had remarkably limited markings, being almost a uniform buff/beige. The wings were just a tad bit darker, maybe a tad bit greyer. I did not notice any head stripe (but doesn't mean that there might not have been one). No major eye-ring (again that I can remember) and certainly no eye bar.

The area had a number of quiet, kind of mumbled chirps. Related? I don't know.

For those unfamiliar with the track, the terrain is a series of shallow, sometimes wide water areas. There are reeds in some stretches and some thickets and low shrubs /palms.

Any help would be more than welcome!

A wren of some kind?

Maybe a female Indigo Bunting?

A wren would have been nice, but the beak was wrong and just didn't behave right. The closest might have been a sedge wren, I think, but still they have a lot more markings that this bird.

I think the female bunting might indeed be right! (The Stokes photo is closer than the Sibley image in this case.)

Thanks!!!