An easier way to get the shiny material is to disassemble the brooches, or maybe it is the charms. But yeah, its much easier than turning the whole field one color.
EDIT: OK, here we go. It's Charms and Caps
Shiny Dew =Antiviral Cap
Shiny Soot=Daemon Charm
Shiny Ember=Poultice Cap or Flame Charm
Shiny Leaf=Forest Charm
Shiny Salt=Angel Charm
Shiny Sand=Earth Charm
I played through the game and only got 1-2 of each of those. Is there an easier way to 'farm' those items somewhere in the game?