HI, I wonder what is the console command to open the character menu, the one where you can change the color of your hair, how tall your character is, etc ?

Not sure if this should be in the cheats forum or not, but I will warn there are permanent consequences for messing with this.

The command is showracemenu

You should probably google it to check out any bad effects from it, and it may be redundant advice, but always have a clean, hard save as back up.

Bad effect is it jumbles around your skills and stats. The command "Setav SKILLNAME ##" can be used to reset them to what they were, so write them down before doing any character changes.

Only if you change the race of your character. If you change his six, the colour of his hair, the shape of his nose, mouth, etc. it won't.