I feed paprika year round. Two tablespoons daily, one every feeding.
Note, this really only works on the coat. The hairs do still bleach, but what happens is, as the bleached hair is regularly shedding out, new dark hairs are coming in at the same rate, so it balances out.
The mane and tail, it would do the same thing, but...That takes forever. Tails don't shed like coats, and they stay long, so even the new dark hairs growing in, just fade again.
I used to dye my horses tail, but it didn't last quite like I wanted, and I really prefer to keep the chemicals out of his tail.
I use the Shapleys. You go through a lot of it, especially with a bay, since I also have to spray his other black points, but it's easier and healthier, since I can just wash it out, and stay natural all other times.
Like you did, I just spray Pepi right over. It lasts all day at shows, and the best method I've liked so far.
"You're just as sane as I am."~Luna Lovegood.