i have a form with a picture on it, and im lookinga t allowing the user to vary the picture. im deliberately choosing pictures of an average colour value, like sunsets and beaches; the whole picture is roughly belonging to one colour channel, so i can set the label caption to a complementing colour channel for it to stand out; light yellow on dark blue for example

but i'd like to know if it's possible, (even by drawing the text on a per-pixel basis?) to render text onto the image as the inverse of the colour underneath it.. hence a picture that was part red, part blue, would have text that was part cyan (on the red part) and part yellow (on the blue bits)

for exampl:

how can i render font text onto the form so that the text is the inverse of the form's background image?