Image aging without photoshop

[Vipershark]

so basically you're trying to do something like this...?

YES except slightly more so than that. How do I do it?

I just reduced the color count down to the 16 colors used by MS-DOS.
Save it in paint as a 16-color bmp file and it'll come out looking exactly like that.

That's not the way that I did it (mine was a bit more complex) but it works the exact same way.