I have a S1 IS. It handles most all colors very accurately except the blue and violet range. The violets have no red in them and look blue, the blues are electric. I have tried all the white balance settings and even used a white piece of paper to set a custom white balance. That helped a little. I have not yet tried a standard grey card for setting white balance, but will be trying that as soon as I get a hold of one. In wide angle scenery shots the blue sky comes out fine, its just in close-ups of flowers, etc.
Has any else had this problem? Any solutions?