Chinese Tourism Visa

Hello,

I am Italian and I will be on a small around the world tour with my belgian husband an our son.
We will be in Colombo in July and we would like to visit China in August, can we apply for a tourist Visa in Colombo even if we are not Sri Lankan residents?
Also do you know if we can still visit Sri Lanka if we leave our passports at the Chinese embassy?

Thank you very much for your help
Francesca