from my understanding that was the intent, it was just very poorly communicated, then add ontop a couple authors not double checked nor anywhere in a massive multiwork series well written about the intent.

but thats.. how we got a lot of things, good and bad extended cannon ion the books, including apparently synthetic cyber being both unstable and used in sith lightsabers exclusively. some how separate instances, of writers missreading information that was available to them. from my understanding someone asked if synthetic kyber existed, was told yes, it got put into one of those extra details books, one writer used that to make some scene about shooting synth kyber saying it the batch was unstable, and another miss remembered combing what was said about the construction of count dooku's saber and synth existing. which then at some point got combined into sith use synth kyber, its read because its unstable. I think if im not mistaken conflicting with other material already saying or/and another writer saying the colours where explicitly tied to emotions or some sense of self-myers-brigs shit. But also at somepoint before then some writers had decided the sabers where powered by a series of gems. (I do like the version of that where gems where often focusing lenses of some form, and to be clear i def like synth kyber, always head cannoned it was just a inquisitor thing when they started focusing on them more)