It's necessary to wait until the temperature light turn from blue to off when you just start the engine each morning?, If I don't do that I'd damage the engine?

No. I can para-phrase Pat Goss on this....
The oil will be lubricating the motor in 4 seconds. Then you can drive.
The blue temp light indicates that the coolant is not yet at operating temperatuer.
You can not operate the heater or defroster until the coolant is warm, but you are free to drive. Warming up the motor is a waste of gas, IMHO.

If you stop the motor for a few moments and start it again, you may see the RED temp light come on until that hot coolant (now hot from not circulating) flows past the radiator.

Pat Goss has a radio call in show for car guys here in D.C.

http://www.scionlife.com/forums/viewtopic.php?t=130056&highlight=

Locked.