Previewers' new tokens should have language specific insides

[RunDevelopment]

I noticed that the new tokens Previewers adds to supported languages have a fixed inside (if any).

This means that the presence of the Previewers plugin can change the way code is highlighted because the Previewers' tokens can match the same (or more) as (than) the tokens of the extended language.
I.e. CSS rgb(0, 0, 0) will be matched as a color token with inside function and punctuation while CSS also matches numbers (with CSS extras) and commas.

[Golmote]

Couldn't we add a ternary check to either merge with the existing inside or create it?

[RunDevelopment]

@Golmote
I don't quite understand what you propose but I don't think we can. To know which inside from the original language to use we would have to know which tokens intersect with a newly added token.
So we would have to check if the intersection of the languages created by two regexes is empty.