+1 to what KJ mentioned above. Have purchased a lot of insert in the market (don't ask me why, possibly mid-life crisis)
The 3 aftermarket ones that I like ootb are (in terms of transition/color accuracy, font and ceramic quality):
1 - GMF v3 Insert (1 serif font is not correct but still pretty decent number engraving and paint is a shade of silver)
2 - The watchesparts one that KJ posted above. Numbers are silver painted and has the correct 18/6 transition. But the 6 font is questionable and at certain angles numbers/font look thin (the paint is not uniformly applied on the edges)
3 -
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
(Has the correct font and blue color is very good. But numbers are painted bright white)
I currently have a build going. Still deciding between #1 and #2