I've just went to Hangzhou for business and return. There were absolutely no checks (yet) on both sides of train stations (Shanghai Hongqiao and Hangzhou East Station) - nobody check the color code or temperature. However, when JW Marriott in Hangzhou found that I'm from Shanghai, I needed to sign a couple of documents swearing that I've never been to Pudong, Shanghai, and then have to download an app and the code on it needed to be green. I had a foreign phone ID so the app wouldn't work from QR code scan, but I manually key in the search term in Wechat and it show up.

This was 2 days ago.