Pastels 640-644
  Phthalocyanine Blue (PB 15:1)
Carbazole Dioxazine PV23
Sodium Aluminum Sulfo-silicate PB 29, Carbonized Bone PBlk.9
Natural Iron Oxide PBR7
+ Titanium (PW 6)
    A set of blues I developed for my Thunderstorm Greys. A dark blue not nearly as grey as the 540 above gives way to a strong deep blue that as it lightens starts to go brownish also.