Explain your idea

The logic units are great, but as circuits get more complex, it can be hard to keep track of what each individual circuit board does. For example if you're trying to automatically manage production in your factories things like Register 0 = AND: White, Orange and Magenta = OR: Register 0, Red `` are a lot harder to understand what they're doing than "Check if both full" and "Shutoff if full/override"

You can rename the Logic Circuits in an anvil like any other item, but that requires experience which, and it would be a lot more convenient if it could be done from directly within the Logic Workbench

An expansion to this idea would be the ability to color the text of said names. For example if I need more than 10 circuits total, and I have Register 0 = AND: White, Orange and name it $\color{#FF00FF}{Both~Full}$ I'll know at a glance that I have at some point output it with Magenta = SET: Register 0 if I need to use it with another Logic Unit, without having to first check what Register I put "Both Full" into, and then check what color I used to output it

Relatedly, if the names of wire colors for inputs and outputs could render as their color, that would also greatly aid in readability

Renaming is in, and colouration in the tooltip too.

I unfortunately can't do coloured text in the name because Mojang deletes my formatting chars when I type them >_>

I'm leaving this open for now, in case a newer version of the game gives us more options!

Figured out how to do the coloured text - you can override the style of the first tooltip in ItemTooltipEvent. Also override getHighlightTip in the item to change the hotbar text when holding the item.

The problem isn't giving it a coloured name, that's easy.
The issue is having players set that colour in the textbox. There isn't a feature for that, and it'd be a lot of effort to add a textbox that supports styling.

I'm leaving that as a project for future me, when I feel like it =p