I hope that someone out there knows alot more about graphics than i
do.

Im currently trying to "hit highlight" a document, given the image and
a set of coordinates of the rectangles to draw (the "hits"). Sounds
easy right?

My problem is this: on black and white images, it works well by using
the setXORmode() to only draw the highlights graphics onto the white
background - in this way it doesnt obscuse the black text (ie, the
color is only overlayed onto the white, not onto the black).

On greyscale images however, i can't figure out how to set a "range"
of color for "white" and a range of color for "black". Meaning i can
only draw translucent rectangles over the graphics object - partially
obscuring the black lettering and making "highlighted" words harder to
see.

Now im fine with having this very slight worry going on - just
changing the color makes things clearer but my boss isnt. after hours
of google searching and reading the API's i thought i would risk
asking you bunch of pro's.

Does anyone know a way i can accomplish this - even a clue as to where
to look would be really really greatly appreciated!

Graeme