In reply to Frank the Husky: >"Does anyone have a simple step by step idea about how to reverse most of the effect?"<
1. Install photo editing software (you could try Picasa).
2 .Open photo in editing software.
3. Play round with sliders (you could try the auto colour or I'm feeling lucky buttons in Picasa). You never know.
4. Even if you get lucky, the images will be compromised. The (limited) information in a JPEG file is pretty much baked in, so put it down to experience, take own camera next time and even if it doesn't do RAW, set the JPEG output style to neutral etc, and don't apply any in-camera effects.