In an nutshell? Nope...there's nothing wrong with your scope.
It's mostly to do with your eyes. They're just not sensitive enough to the very low levels of light to reveal much colour.
Even in my 9.25" scope the Orion neb is pretty much black and white.
Saturn shows a predominantly gentle yellow/gold colour with hints of a red equatorial band occasionally.
Jupiter offers a little more in the way of colour, but that's an early morning object at the moment. Wait a month or two...but even then it's quite subtle.
So don't worry. Your scope is fine. Look more for detail than colour
There are plenty of stars to view which will show you colours...end even double stars where the colours are different.