OPAQUE COLORS:
Burnt Umber
All Cadiums
Chronium Oxide
All Whites
Naples Yellow
Raw Umber
SEMI OPAQUE COLORS:
Lamp Black
Lemon Yellow
Permanent Green
Yellow Ochre
TRANSPARENT COLORS:
All Untramarines
Alizarin Crison (cool)
Burnt Sienna
Viridian Green
SEMI TRANSPARENT COLORS:
Cobalt Blue
Ivory Black
Phthalo Blue and Green
Raw Sienna
Prussian Blue
Having this list will also help when "glazing" and building color layers.