Detecting Colour and Monochrome Monitors

Detecting whether a user has a colour or monochrome video card is a trivial task. The BIOS data segment has a value in it for this information. Below is a function (in ISO C) to retrieve this:

The Function

/* 
    Video card mono/colour detection.
    Return values:  false=mono
                    true=colour
*/
_Bool detectVideoType(void)
{
    _Bool type;
    char c=(*(volatile USHORT*)0x410)&0x30;

    //c can be 0x00 or 0x20 for colour, 0x30 for mono.
    if(c==0x30){
        return(true);	//Monochrome monitor.
    } else {
        return(false);	//Colour monitor.
    }
}