Why does color adjustment make photo grainy?

[Carrie Mat]

I have a lovely sharp photo and while it looks just right on the screen, it needs some color adjustment (saturation) to print out with the correct color. However, when I correct the color to print correctly, the picture becomes grainy looking. Increasing the pixels seems to have no effect. Hope someone can help. Many thanks!

[Chuck Snyder]

Carrie - what are the pixel dimensions of your original image (look in Image>Resize>Image Size)? Making a good print requires a relatively large number of pixels to minimize the grainy appearance.

Chuck

[Beth Haney]

And to add to Chuck's post - you said "Increasing the pixels seems to have no effect". Does this mean that you've done some resizing upward? Generally, if you have an image of a given size and try to make it larger, you either reduce the resolution by stretching the available number pixels to cover the expanded area or you use "resampling." Either can effect the quality of the image. Resampling upward causes Elements to "make up" information about pixels, which can diminish the quality, too. Might either of those things happened?