Build colored and formatted text with the section-sign codes for signs, chat, MOTD and server names - with a live preview. Free.
A section sign followed by a code (like the code for red) sets the color of the text that follows. Formatting codes add bold, italic, underline and more. A reset code returns to normal.
Vanilla Minecraft uses the section sign. Many server plugins let you type an ampersand instead, which they convert. Pick your symbol below.