I have at least 50 digital photos stored in a file. In thunmbnail view they're OK When I enlarge and open them in Software ACDSee the black or darker portions of each picture show up as a very bright almost neon green. How do I correct.

   What is the extension of the photo files?  Is it .GIF or .JPG?  If it is GIF, the background color (which is supposed to show up transparent or the color of what is behind the picture) of the file is what is showing up as neon green.