I try to disturb unguicularis as little as possible, and I wouldn't count on its being completely finished blooming right now, but it shouldn't cause any harm to remove only the foliage that's obviously dead. I'd just cut it off above the rhizome, leaving that intact unless it's necessary to move or divide the plant,and being careful not to harm the new leaf buds which will be formed at the base of the old stems now. Seems like a lot of tedious work, especially if your patch is on the large side. I like Felder Rushing's comment that "brown is also a color"!

Just to add my own confirmation to the mix, I agree with what bubba62 said. As long as a leaf is green it's feeding the plant, so it's best to only trim those that are obviously dead.

Not only is brown also a color, I always have a hard time throwing out the beardless iris foliage. Some years, I've actually bundled it and hung it to dry so I can use it in dry arrangements.

You know what they say: beauty is in the eye of the beholder. :)

Brock