When you inspect a sign that has hex colors it shows the wrong colors:

How to reproduce:
Get a plugin that allows you to use hex colors on signs such as SignEdit: https://www.spigotmc.org/resources/signedit-for-bukkit.47604/. Use signedit to set the line on a sign with hex codes, for example: /sign set 1 &#abc123Hello and then right click with /co i on the sign.

Already fixed in 12f2000