Iron Signs themselves are not much better than Vanilla wooden signs. They are inexpensive, and stack up to 64, but they are just dull gray, slightly rusted pieces of iron plates.
!Screenshot
Their crafting recipes are similar to the Vanilla wooden signs:
!Crafting Iron Sign !Crafting Hanging Iron Sign
But Iron Signs can be painted to all the colors of Minecraft:
!Painting a Yellow Sign
Or even more efficiently, at the time of their creation:
!Crafting a Yellow Sign
The vibrant, high contrast, painted signs then can be used to convey information to your friends:
!Screenshot
Or to your enemies:
!Screenshot
Or to your customers:
!Screenshot
Since 1.0.2 with sign text coloring and formatting:
!Sign editing
Standard MIT license. Feel free to learn from it and incorporate it in your own projects.
Some parts of the code are based on the source code of Text Utilities, which is LGPL-3 licensed.
Available on GitLab or on GitHub.
The mod has not been tested extensively in large modpacks and on large servers. Feedback is welcome.
Email: Pintér Gábor pinter.gabor@gmx.at
Thanks to Kaupenjoe for his excellent Modding By Kaupenjoe: Minecraft Modding 1.20.X for Fabric course.
Thanks to Chaws for making available the source code of Text Utilities.
My other mods on Modrinth and on CurseForge.

Create signs in all colors of Minecraft.