Monochrome postmark: stamp used with a single-colored ink pad as intended style
black
orange
red
brown
blue
woad blue
green
greenish blue
violet
magenta
Bicolour postmark: stamp used with a split two-colour ink pad as intended style
blue/ red
blue/ yellow
green/ red
red/ black
red/ blue
black/ red
Tricolour postmark: stamp used with a split three-colour ink pad as intended style
green/ violet/ yellow
black/ red/ yellow
blue/ brown/ red
red/ green/ blue