Anonymous structs

SAn

I need to do that:

union tColor
{
  struct //anonymous struct
  {
    unsigned char r,g,b;
  };

  unsigned char channels[3];
};

This works as intended in MSVC:

tColor color;
color.r=100;
color.g=150;
color.b=200;
color.channels[1]==150; //true

But i still worry if this according to the C++ standard.

Also I wonder if I can use anonymous arrays:

union tColor
{
  struct
  {
    unsigned char r,g,b;
  };

  unsigned char[3]; //anonymous array ?
};

to do the following:

tColor color;
color.r=100;
color[1]=150;
color[2]=200;

Or I should define operator[] ?