Single color from a multi-color picture?

[Egg Bramhill]

Bill
Not quite sure what you want here. Try some of these:
Import image.
Delete it.
Goto bitmap gallery
Select deleted bitmap from the gallery
Select Plug-ins (you don't have to have any)
Select bitmap effects
Select colour depth
You've got 3 different mono effects, 1 greyscale and some others

The example is a mono (bayer)

Egg