Currently on the shadowlands alpha, there is an ink trader similar to how we have roseate traders for old world inks, but now the ink required is umbral ink instead of roseate and you can buy both roseate and sallow… for 1 Umbral Ink Each. An increase in the price for the Sallow pigment to 10 Umbral Ink like it is on the uncommon rarity old world inks would be very beneficial to the economy and overall value of legion glyphs. Notably, some glyphs in Legion take up to 64 total ink to make, so the price of roseate may stay decent depending on how difficult umbral inks are to get. The old-er glyphs are still totally smoked though at only 3 or 4 inks each.