Living plant is green, especially after watering. Brown is dead. A photo might help.

Have you tried soaking it longer? A few hours or even overnight, repeated weekly as needed in addition to dunking or spraying heavily (until dripping, and good air circulation) daily or every other day depending where you live. I rescued mine this way, at that time it was yellowing and very dehydrated. Now, it's green and happy.

Try posting a photo to better identify the problem and care.

If you don't know what kind of Tillandsia it is, try to post a picture so we can help you determine how much water it needs. If you can't post a picture, we can suggests sites with lots of pictures that may help you identify your plant.