use of colors of an image?

[Tiemo Hollmann TB]

Hi,

I wonder what you can use the colors and patterns of an image for? I havn't
used them before and when I try to set one of the eight colors, either of an
empty image or an actual image, nothing is seen. I was hoping I can use them
as a kind of hilite color, or as a kind of a blend level of the image, but
so far I must miss something to use them.

 

What I would like to have is a "hilite blend level" as a kind of "hilite
icon" or "hilite color", with which I could show another state of the image,
when clicked. The only other way I see so far is to work with two different
images, which show the different state and scripting both images to switch,
or using a third "overlay graphic" with ink=noop (thanks Klaus!) to control
the switch of the images, when clicked. But perhaps there is a way to work
with only one image?

 

Thanks for any hint and have a nice WE

Tiemo