The different color (themes) for weather connects to different caching servers, that is why they are not exactly the same, the weather data is updated every 4 hours. So depending on when your data was cached, it might be off by a few degrees from time to time.
The reasoning behind having different servers is due to the large volume of data requests. If we were to use a single server it will quickly be bogged down to a crawl till it crashes due to the number of requests our weather data servers are handling. Imagine having more than 60 thousand request every few secs. So different servers for different themes was the solution. Thats why you get different data from time to time between the 2 servers.