We are at day 18 of flower and we noticed on one of the purple punch plants that on one bud, there are some orange hairs forming and they are wilting. The lights are about 26 inches away and we are watering when the soil is dry. What could be happening?
Those pistils will mature, and as the plant grows further more white pistils (and calyxes) will grow and overtake the mature ones. Nothing to worry about.
That's normal mate, the oldest pistils will die off and new ones will replace them, this process will keep repeating until you have lovely buds and then harvest time.