These are the codes for text colors on signs. Enter the code then type your text.
If you want to type this symbol ( § ) instead of copying and pasting, this is the method depending on your OS:
Windows: Alt + Numpad 0167
Linux: Compose key + S O
Chat colors:
If you want to color your chat text, type: /color (your text)
Typing /colors will provide the list of color names.
§0 Black
§1 Dark Blue
§2 Dark Green
§3 Dark Aqua
§4 Dark Red
§5 Dark Purple
§6 Gold
§7 Gray
§8 Dark Gray
§9 Blue
§a Green
§b Aqua
§c Red
§d Light Purple
§e Yellow
§f White