Casting ints to enums in C#

Question

There is something that I cannot understand in C#. You can cast an out-of-range int into an enum and the compiler does not flinch. Imagine this

Answer 1

That is unexpected... what we really want is to control the casting... for instance:

Colour eco;
if(Enum.TryParse("17", out eco)) //Parse successfully??
{
  var isValid = Enum.GetValues(typeof (Colour)).Cast().Contains(eco);
  if(isValid)
  {
     //It is really a valid Enum Colour. Here is safe!
  }
}