C++ :: Operations On Enumerations

I'm used to writing enums for enumerated types. However I have this:

enum Colour
{
BLUE = 0x01,
BLACK = 0x02,
WHITE = 0x04,
GREEN = 0x08,
RED = 0x10
};

Now each of the enumerated types are not exclusive, so I'd like to do this:

Colour c = BLUE | BLACK;

Of course that doesn't work. gcc gives "invalid conversion from 'int' to 'Colour' [-fpermissive]".

typedef int Colour;
static const Colour BLUE = 0x01;
static const Colour BLACK = 0x02;
static const Colour WHITE = 0x04;
static const Colour GREEN = 0x08;
static const Colour RED = 0x10;