２色の相対から自動的にステータスバーの色を選出 ref: http://qiita.com/noppefoxwolf/items/56c9108c2554c594b151

file0.m

-(UIStatusBarStyle)statusbarstyleWithBaseColor:(UIColor*)baseColor ButtonColor:(UIColor*)buttonColor{
    CGFloat b1,b2;
    [baseColor   getHue:nil saturation:nil brightness:&b1 alpha:nil];
    [buttonColor getHue:nil saturation:nil brightness:&b2 alpha:nil];
    return b1>b2?UIStatusBarStyleLightContent:UIStatusBarStyleDefault;
}