EnumUtils.ConvertTo

EnumUtils.cs

class EnumUtils
{
    public static T ConvertTo<T, S>(S source)
        where T : struct
        where S : struct
    {
        if (!typeof(T).IsEnum)
            throw new ArgumentException("T must be an enumerated type");

        if (!typeof(S).IsEnum)
            throw new ArgumentException("S must be an enumerated type");

        string sourceName = Enum.GetName(typeof(S), source);

        if (!Enum.IsDefined(typeof(T), sourceName))
            throw new ArgumentException($"enum name {sourceName} does not exist in {typeof(T).Name} enum.", nameof(source));

        return (T)Enum.Parse(typeof(T), sourceName);
    }
}

Example.cs

class Program
{
    enum ColorDTO
    {
        white,
        black

    }
    enum Color
    {
        black,
        white
    }

    enum NoColor
    {

    }

    static void Main(string[] args)
    {
        ColorDTO dto = ColorDTO.black;
        Color c = EnumUtils.ConvertTo<Color, ColorDTO>(dto);
        Console.WriteLine(c);//Prints black
        NoColor nc = EnumUtils.ConvertTo<NoColor, ColorDTO>(dto);//Throws
    }
}