The W290 goes from ISO 80 up to ISO 3,200, but usability drops off significantly above ISO 400 (typical of cameras in its class). However, even at ISO 80, photos viewed at full size have a grain to them that only gets more pronounced as sensitivities get higher. It had little-to-no impact on large prints (13x19 and below) made from test shots taken up to IS0 400. If you're planning to make prints that large, just keep the ISO as low as possible.
This was taken at ISO 80 and is an extreme example of the graininess/artifacting that's visible at 100 percent. It's not really noticeable in prints at 8x10 inches or smaller. More of a concern is the overall softness of the image.
Colors produced by the W290 are pretty accurate and exposure was good as well. Sony includes its Dynamic Range Optimization feature on this model, too, which helps bring out details that would otherwise be lost in shadows.