Where is the best place to declare enums?

Question

C++ / C#

Let's say I have a class:

class SomeClass {
    public SomeEnum someEnum;
}

And where should I better declare the SomeEnum enum:

in class

class SomeClass {
    public SomeEnum someEnum;

    public enum SomeEnum {
        Red, Green, Blue
    }
}

or

outside of it?

class SomeClass {
    public SomeEnum someEnum;
}

enum SomeEnum {
    Red, Green, Blue
}

Answer 1

If it refers only to the class, then inside it, if not, then outside