Halki was a pretty experience. I think that would describe the village best.
What makes it colorful is literally the colours that the buildings have been painted in, mostly pastel colours. Some are darker to the red clay side of the spectrum, but they are mostly varied to the yellow - orange side, making the narrow streets quite playful but not gaudy. And everywhere there are the colours of flowers and plenty of green that goes with it.
Halki is a very “neat” village. Everything seems to be in place. Its alleys are “decorated” with small, colourful traditional cafés, a few taverns, some cute shops and many old houses. The main road cuts the village in half. It is quite weird but the first time I visited Halki, I simply ignored it thinking it is almost uninhabited. How untrue! It was only after my boyfriend insisted again and again that I decided to take a second look. And I loved it.
They say it used to be the capital of Naxos some decades ago (I can’t be sure till when exactly). Its past wealth can still be seen. Not many people live there now on a permanent basis, but during the summer it gets many visitors. It is definitely a must see destination on Naxos.