Travelling via Hong Kong

I am a US Green Card holder with Indian passport and my spouse is a US citizen. We are travelling to Delhi via Hongkong on Cathay Pacific. On the way in, the lay over time is exactly 10 hours. ETA is 0700 hrs and connecting flight for Delhi leaves at 1700 hrs. Questions:

1. Do either of us need a transit visa if we stay at the airport?
alternately
2. In case of cooling our heels in the airport for 10 hours if we want to go in to city, do we need tourist visas?

thank you,
deb