I have no real interest in mod development at the moment, so I am archiving this. Feel free to fork, and consider some of the community forks/
BetterBlockOutline is a client sided Minecraft mod that allows for ample customization of the block outline. Everything from color customization to debug information.
There are different color effects you can apply to the fill color or the outline color. Chroma, blink, and more coming!
MaLiLib is required run and Mod Menu for configuration.
Join the Discord for help.
More in ./screenshots
If you want to support this mod I would heavily appreciate it if you would share it with your friends. Feel free to come to the Discord to submit bugs, request features, or just hang around.
Code & Mastermind: DarkKronicle
Language man: Chronos22 (You would not understand the mod without this guy)