can we invert an image such that its true color can be retrieved?

i want to invert the color of image such that it retrieves its original color at the place of a specific color.

Answer 1

[Image Analyst]

See this: http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

Given what you say, about the only thing I can assume is that somehow the true color image got inverted so you need to invert it back:

trueRGB = 255 - rgbImage;

Then use imfreehand(), gpinput(), or indexing to get the color at "the place". Better information will get you better answers.