Photographs often show vivid color in nebulae. The human eye can not see those colors well with ANY telescope. The hobby consists of seeing faint, grayish fuzzies. On brighter objects such as the Moon and Jupiter, the eye more closely matches photographs, but asking for pictures to match the view from a 6-inch (or any) scope is a hard request to match.
You'll get decent views of the Moon, Jupiter, and Saturn, and for maybe 2 months every 2 years Mars will look nice (the rest of the time Mars is too small to see well). Under dark skies you'll see many of the brightest Messier objects well (though grayish). Still, if there's any way you can afford to step up to an 8-inch scope, that small difference in aperture makes images 77% brighter. You cross a threshold into a more serious instrument at 8 inches, I think. Still, my first scope 27 years ago was 6 inches. At the time that was a fairly standard size for amateurs. Now it seems small, since scopes have gotten so much cheaper.

--Dan Johnson