cultivar color no that's impossible.
The Lapin cherry is red and not of this color.
When a few chemicals I doubt it too but why not.
The mutation is possible but I have never seen it like this, I saw cherries stark gold ( color yellow ) take on some cherry the color of the Cherry Napoleon ( color red and yellow ) when stark gold is grafted on Napoleon.
But I've never seen this, except due to hail (but there are traces of impact if that's the case).
However even hail (unless it is very strong to destroy the fruit) does change the color to maturity