颜色设置: 指定RGB,參数是:红.绿.黄.透明度,范围是0-1 + (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha; 指定HSB,參数是:色调(hue),饱和的(saturation),亮度(brightness) + (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturati…