Brom Dandy in Balefort drops level 19 pinks in either level 4 or 5. Get your 1024 tomes quest first, as it will take about 50 runs of level 5, or about 10 runs of the 5 map sequence to get those 1024 tomes. And I have gotten four pinks so far, at about the 75% mark (about 250 tomes to go).