These are very immature green grapes. They will be ripe sometime in September I would wager. I shot this image as an in-camera JPEG and applied a fairly normal-for-me web reduction USM scheme of like 200%, .3 pixel radius, threshold of Zero with a series of re-sizing and resamplings. My last USM pass was reduced to 140%, .2,0. Overall, the color accuracy on this shaded grape cluster is very good I think. I didn't have quite enough depth of field at f/6.3 to do this scene justice. As somebody who shoots primarily for the world wide web, I think the D70's image workability and quality are both plenty good enough.