When the electrician wiring, the fire wire and the neutral wire are both blue wires, and the ground

OK. This is just because there is no other color wire on hand and not very standardized method, it is best to use colored electrical tape on the terminal head, the kitchen is used as a rice cooker wire to ensure the load power of the wire, because the power of the rice cooker is relatively large and according to the yellow wire as the ground wire connection.

There is no definite answer to this. There is no mandatory rule on what wire to connect due to the color of the wire. Although there are some default practices, it is common for electricians to confirm with field meters for safety. And not credulously believing in the red convention.

In general, red is filigree (brown is also used). Blue or black is the zero line. The green or yellow or yellow-green two-color line is the zero line. There are also green for the zero line.

After switching, the deloaded wire is generally not red. Opportunities may be blue, etc.