Sending message through CommandSender.sendMessage(String) doesn't parse colours.

[MisterCavespider]

Exactly as the title states.

sender.sendMessage("&6TEXT"); wont parse the colour.

[picknchew]

The ampersand, & is not the color character for Minecraft. It is actually the section sign, §.

[mastercoms]

You have to do sender.sendMessage(ChatColor.GOLD + "TEXT"). & and section signs will not work as they are not parsed by Bukkit by default. EssentialsChat will add this functionality.

[aramperes]

Alternatively to what @mastercoms said, you can use ChatColor.translateAlternateColorCodes('&', "&6TEXT"); (javadoc)

[gdude2002]

Yup, out of experience with Bukkit, I can agree with everyone else here. sendMessage does not parse the colour, and that is expected behavior. There are plugins which change that, but you shouldn't rely on their presence.