Upvote:0
If the visa states "valid for: Schengen countries" (or similiar, I only know the German phrase) then it is a USV visa, which means you are not restricted to certain countries. If the type of the visa is C (which is probably the case for you), then you should be able to go whereever you want. In general visa usually contain all information: The area for which it is valid, the valid time period and the duration of stay. If there are no restriction on a visa, then there are no restrictions for you. If someone tells you any different, call your embassy. What is much more important in your case is your travel health insurance. If you go to Rome you are no longer covered by your employer and maybe also not by a private insurance. Get a travel health insurance for just a few Euro (between 5 and 10 Euro one time payment) and you are covered worldwide for a whole year.
Upvote:4
The answer is unfortunately not as simple as implied by haferblues in his answer. Yes, your visa is valid for the entire Schengen area within the period of validity stated on the visa, but when you applied for the visa, you also provided a purpose and itinerary for the planned trip and you are within reason supposed to use the visa for this purpose and not for a completely different itinerary.
Your original plan obviously had the Netherlands as main destination (since the visa was issued by the Dutch embassy as competent authority) and you are now not planning to go to the Netherlands at all. Your outcome is likely to depend on the amount of scrutiny conducted by the immigration officer when you enter the Schengen area. If you are lucky, you will simply be stamped in and noone will notice the change in itinerary. If you are picked for a more extensive examination, the immigration officer is likely to find out that your current plans do not match the purpose for which the visa was issued, and can refuse entry.