I believe those who didn't know what's ! can just google, or else every kata requires explanation of them and becomes annoying!

ToInt32

3 and 2 are numbers.

If you are curious, compare this to my solution.

Yeah, GetColor() has to be added to the description or remove GetColor() from the tests (C#).

Oof, good to know

thing to note is that value is a keyword, so I often try to avoid using it

another option is to just return rather than keeping a character result value :)

This isn't always true
solution('abcc', 'bc') shoud return false, but will return true with your solution
A test scenario should be added for c# for this case

c# still is not able to be completed because of rounding

good, using linq :)