I'd like to open a theory-type discussion on late season color. Most of the hybrids I deal with are 419, so let's keep that as the subject cultivar. What have you found to be the secret to maintaining late season color right up until the first frost? You see that sports field managers at the major universities do a good job with this. At UGA's Sanford Stadium for example, they have not overseeded with rye but the turf still looks great. (I saw it in person last weekend) Common practice is to not apply more than miniscule amounts of N after mid-September, so let's throw that out. I manage one lawn in particular that had a granular application of Fe back in August. That lawn is holding its color very well to this point. Another lawn I manage was treated with liquid Fe in September. However with this lawn I've noticed less response from that treatment. Granted, the soil condition of these are not yet optimal since I took these over only a few months ago. Soil tests were recently completed. I suspect that with the now known pH issue, the Fe application was not as effective. Both of these received the high potassium application back in September as well. Is the secret really Fe? Or is there some other trick to holding the color later in the season? I'd like to know if any studies have been done on this.