Without greater context I recommend a simple [`ReplaceAll`](https://reference.wolfram.com/language/ref/ReplaceAll.html) operation, to work on all appearances of `Style` at any level.

    {1, Style[2, Red], 3, Style[4, Red]} /. Style[x_, ___] :> x

>     {1, 2, 3, 4}

If you want to strip `Style` from *only* numbers then you could use something like:

    /. Style[x_?NumericQ, ___] :> x