I am a western woman travelling to Guangzhou for up to 2 weeks of technical meetings in August.

What I am have read about women's business dress is that it should be very formal and conservative, eg, suits, plain coloured long sleeved shirts, closed shoes etc. Are these rules likely to apply in an IT environment? Also can I wear these same type of clothes if going out for dinner with Chinese colleagues or should I bring some different clothes for this. Also what about for shopping and sightseeing on the weekend. Is something like a knee length floral dress with sleeves to mid upper arm and sandals okay? Thank you.