This is a plugin that allows you to set a sign's individual lines without removing the others. It even has a feature where it can scroll your text if you want it to. It also supports color codes!
- Tested Minecraft Versions:
To set a sign line, use "/setline <line number> <type> <your message>" while you are looking at a sign.
if you want plain text replace <type> with <text>.
If you just want a scrolling line replace <type> with <scroller>.
To make a line blank or remove the scroller, use "/removeline <line number>" while you are looking at a sign.