+ (NSColor *)gr_randomColor
{
CGFloat red = (CGFloat)random()/(CGFloat)RAND_MAX;
CGFloat blue = (CGFloat)random()/(CGFloat)RAND_MAX;
CGFloat green = (CGFloat)random()/(CGFloat)RAND_MAX;
return [NSColor colorWithCalibratedRed:red green:green blue:blue alpha:1.0];
}