good tip W4C....i don't have photoshop, so i have to do it on my camera. but i will file that away should i ever get that program.
to do this on a cannon:
when you are ready to take a picture
1. push functions/set
2. switch from automatic to color accent (probably from pic of a camera to a medicine dropper with an A pic)
3. push funct/set again
you are almost ready....
1. push display
2. select color to be displayed (on the 1100, you scroll to the left or right while focusing on the color to pick up, and it will put it on the screen)
3. push func/display again
you should notice now on the screen that whatever color you chose is the only color there.
lastly:
1. take the picture as normal
...i have noticed this works best outside or in a very light room.
it seems complicated, but once you get the hang of it...it is easy to switch back and forth