iOS中，常用的获取RGB颜色值和十六进制颜色值转换方法的宏定义。
#define RGB(r,g,b) [UIColor colorWithRed:(r)/255.f
green:(g)/255.f
blue:(b)/255.f
alpha:1.f]
#define RGBA(r,g,b,a) [UIColor colorWithRed:(r)/255.f \
green:(g)/255.f \
blue:(b)/255.f \
alpha:(a)]
#define RGBOF(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 \
alpha:1.0]
#define RGBA_OF(rgbValue) [UIColor colorWithRed:((float)(((rgbValue) & 0xFF000000) >> 24))/255.0 \
green:((float)(((rgbValue) & 0x00FF0000) >> 16))/255.0 \
blue:((float)(rgbValue & 0x0000FF00) >> 8)/255.0 \
alpha:((float)(rgbValue & 0x000000FF))/255.0]
#define RGBAOF(v, a) [UIColor colorWithRed:((float)(((v) & 0xFF0000) >> 16))/255.0 \
green:((float)(((v) & 0x00FF00) >> 8))/255.0 \
blue:((float)(v & 0x0000FF))/255.0 \
alpha:a]