How to map tinyint to c# byte using entityframework code first migration

I am trying to map tinyint column to byte property in c#How to achieve this efficiently. I want to store the values null, 0 and 1 to the database column. Please find below my code. Can anyone help me whether the following is the right approach?

public enum TriState : byte
{
    Null = 0,
    True = 1,
    False =2
}

[NotMapped]
public TriState AuthorisationStatus { get; set; }

[Column("AuthorisationStatus")]
public byte AuthorisationStatusByte {
    get
    {
        return Convert.ToByte(AuthorisationStatus.ToString());
    }
    private set
    {
        AuthorisationStatus = EnumExtensions.ParseEnum<TriState>(value);
    }
}

public static T ParseEnum<T>(byte value)
{
    return (T)Enum.Parse(typeof(T), value.ToString(), true);
}

Thanks