Filing off the anodized layer is indeed bound to look awful.
Technically it can be done in a garage, but spot and/or intact application might be difficult. Strict color matching against Apple made things would be impossible.
People do home anodizing all the time, but colored home anodizing on electronics is very rare.
The way to do it would be wrapping it in, say, a wet paper towel with your strong acid solution (but not sulfuric, because that would turn the paper into pure carbon foam) and running outside current from the laptop through the paper to a cathode, or vice versa.
Anodizing works as follows:
1. Take the MacBook apart
2. Clean it
3. Chemical bath to remove old anodized layer
4. Clean it again
5. Chemical bath with power supply attached. applied voltage+current and duration will determine hardness and thickness of the anodized layer.
6. Clean it
7. Dye it.
8. Seal the dye in a hot water bath.
It’s fairly straight forward to do.
In the context of a MacBook, it’s not. Removing just the aluminium components and leaving everything that doesn’t like baths undamaged is practically impossible for amateurs. I’m not sure it’s something many professionals would take on.
https://lowendmac.com/2024/ryan-andersons-colorized-anodized...
Otherwise known as "remove everything from the chassis, leaving only the chassis."
But do so in a way that lets you fully re-assemble it later on, after you've finished the re-anodising.
> 7. Dye it.
Why the dye? I thought anodising's colour comes only from the voltage used, with no dye needed.
ie you can pick the colour you want, but you need to get the voltage correct for that colour
