I don't think there's anything wrong with calling yourself Indonesian. Even though both my parents are pure Chinese, I was born in America and English is my first language, so I'm an American. Yeah, I still get hit with a few stereotypes now and then, but racism is other people's problem, not yours.
On the other side of the coin, I also think it'd be a good experience to get in touch with your Dutch and Chinese roots. Learn to speak the languages if you can, asking your parents for help along the way. That way you don't have to be embarrassed to call yourself Dutch/Chinese-Indonesian.
Jam it back in, in the dark.