While loggin in HDFC Bank Net Banking i am getting Classic, does it mean my account type has been changed?

No you still have the basic account

Had it been classic the colour would have changed to yellow

I think the Golden Yellow color is for Preferred Banking ..

Your account has been upgraded to classic. You will enjoy free classic service for a year. After that, you will be charged Rs.100+taxes for every quarter. Some of the benefits that I know are given below. Not sure whether all of them are still there.
1. You are now not required to maintain Average monthly balance.
2. You will not be charged for sms alerts.
3. Your debit card will be upgraded to platinum card free of cost, this card given 1% cashback on transactions.
4. You will be eligible for free Hdfc Regalia First credit card.
5. You will have a personal banker.
6. Lower interest rates on personal loans (not sure about this)

Become Imperia and enjoy host of benefit. Customer loots.
Preferred is neutral both customer and bank loots
Classic is looted by bank

whats the NRV to become a classic customer?
@Cody