When the subject matter and/or the lighting is high in contrast, the Vivid picture setting is often a recipe for disaster. However, on FLAT-lighted days, or with really low-contrast subject matter, it can look simply wonderful. If you use Vivid, you might want to consider that it will tend to emphasize contrast, and saturation, which on things like brown-and-white dogs, and black-and white cats, illuminated by high-contrast window-lighting, is the proverbial recipe for disaster I alluded to earlier. Window lighting in most normal homes is quite high in contrast...unless there is a LOT of fill lighting, the window side is very bright, and the shadowed side quickly drops wayyyyy off in brightness. "Vivid" on the "older" Nikons like the D70 and D80 was actually reasonably useful, but on the newer models, Nikon's baseline tone curve seems much,much hotter, and so Vivid is now kind of clown-color-like, like Fuji Velvia...it's just short of garish on the D3000,D3100,D5000, D5100...but as I said, on FLAT-lighted days, Vivid can actually look pretty good--with no post processing.
I would say try Direct Print as opposed to Vivid, if you want to try another pre-set value. I think it is a good idea to shoot RAW + JPEG, and then you will have the RAW file for serious manipulations, and ALSO the benefit of a JPEG file that has the appropriate degree of JPEG processing already done to it. Nikon cameras all have subtly different pre-set characteristics thagt vary by model and sort of also by generation of camera. Nikon's noise reduction, their degree of in-camera sharpening, AND their in-camera chromatic aberration removal--all that stuff is tied in to the lens and the CPU information conveyed to the camera. The automatic CA removal is done on JPEG files, but not on RAW files. The noise reduction is custom-designed for each sensor and camera. Same with the pre-set picture controls. Until you become pretty good at processing raw images, I would say shoot RAW+ JPEG (either Medium size Jpeg with Fine compression OR Large-sized JPEG, with Fine Compression) and see what the camera and its internal processing can do. Experiment a bit...try Vivid in the fog some time!!! Try Vivid on cloudy days...but stay away from vivid under high-contrast lighting scenarios, or with B&W colored kitty cats that are adorable as heck!!!
There are different schools of thought on how best to use a d-slr, and the controls. Nikon has designed some good cameras that operate very differently from other companies' cameras, like with the built-in image editing, color-AWARE metering, and so on...the consumer cameras have the potential to deliver almost perfect images in JPEG for with D-Lighting applied an all that--but you need to learn exactly HOW the camera works. And when to set it up one way, and when not to set it that same way. The Baby Nikons are geared more toward LESS post-processing, and so their picture control pre-sets can be pretty extreme.