In what temperature range can I use the first and second generation Yeelight bulbs? I am planning to use them outside in my balcony.
Both are 2700K to 6500K.
I think he means the temperature range for electric circuit to work. And maybe also the humidity range. I suppose not more than 55°C or 80% of umidity.
Yes, I meant weather temperature 
(BTW it would be impressive if the bulb was withstanding 6500K) 
Do you have one of these? It should be reported on the box or manual quick reference
I have several V1 and V2 bulb in white and coulour ones but I just could not find this information enywhere. I would like to use them outside and here the temperatures are between -10°C to 40°C during a year.
Here you the infos Download Yeelight Smart Bulb Manual
Exactly the range you need 0-85% humidity range and -10°C/40°C of temperature range.