Clip off the bloom panicles that are brown since they won't recover. In future if they are still in the pots when a freeze is predicted, bring them into a shed, garage, basement, or even the kitchen until it's less frigid; anywhere they will not freeze.

Do you know what cultivar they are? Some will put out additional blooms on new growth, but others only bloom once in spring on buds that were set during the previous growing season, so depending on type you might or might not get additional blooms.

Oh, no! Hope your shrubs rebloom so you can get more blooms in the summer. If the browned out blooms show no signs of fungal infections, consider recycling them and using them as mulch.

These are florists' hydrangeas - grown under very specialized greenhouse conditions to bloom very young and well out of season and are not the slightest bit adapted for cold. Blooming hydrangeas at this time of year are intended as temporary houseplants - sorry :-(

With only the flowers affected, you are still in good shape - the foliage looks untouched. Just cut them off right below the blossoms and right above the next pair of leaves. The advice given above is valid for the potential to produce some additional flowers later but I wouldn't count on it - greenhouse hydrangeas are typically not the reblooming varieties.

The important issue is how to keep your plant alive long enough to be able to transition it out of doors when the weather becomes suitable. Hydrangeas do not make great houseplants - not enough light indoors and usually too dry and too warm conditions. Keep it in a cool but very bright location (out of direct sun) and keep the soil just moist to the touch.

When the weather warms properly, you can gradually transition your plant to the outdoors and plant in the ground. Knowing where you live can help with more directed advice.

I appreciate the comments! Thanks!

I feel like I already knew that I'd have to cut off the absolutely beautiful blooms before I even posted, but was hoping someone would have advice to make them restore to their color!

I'll grieve the loss of the blooms and cut them :( I'll just be thankful the leaves weren't affected.