create
// Convenience methods for creating colors
+ (UIColor *)colorWithWhite:(CGFloat)white alpha:(CGFloat)alpha;
+ (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha;
+ (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha;
+ (UIColor *)colorWithCGColor:(CGColorRef)cgColor;
+ (UIColor *)colorWithPatternImage:(UIImage *)image;
#if __has_include(<CoreImage/CoreImage.h>)
+ (UIColor *)colorWithCIColor:(CIColor *)ciColor NS_AVAILABLE_IOS(5_0);
#endif
解释：
支持gray colorspace支持HSB colorspace支持RGB colorspace支持Quartz color，native color space of Quartz color支持pattern image，tiled模式绘制，默认相位为0，即image的top-left corner与绘制区域原点对齐支持Core Image color
init
// Initializers for creating colors
- (UIColor *)initWithWhite:(CGFloat)white alpha:(CGFloat)alpha;
- (UIColor *)initWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha;
- (UIColor *)initWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha;
- (UIColor *)initWithCGColor:(CGColorRef)cgColor;
- (UIColor *)initWithPatternImage:(UIImage*)image;
#if __has_include(<CoreImage/CoreImage.h>)
- (UIColor *)initWithCIColor:(CIColor *)ciColor NS_AVAILABLE_IOS(5_0);
#endif注：对应create各种创建UIColor模式
预定义颜色
// Some convenience methods to create colors. These colors will be as calibrated as possible.
// These colors are cached.
+ (UIColor *)blackColor; // 0.0 white
+ (UIColor *)darkGrayColor; // 0.333 white
+ (UIColor *)lightGrayColor; // 0.667 white
+ (UIColor *)whiteColor; // 1.0 white
+ (UIColor *)grayColor; // 0.5 white
+ (UIColor *)redColor; // 1.0, 0.0, 0.0 RGB
+ (UIColor *)greenColor; // 0.0, 1.0, 0.0 RGB
+ (UIColor *)blueColor; // 0.0, 0.0, 1.0 RGB
+ (UIColor *)cyanColor; // 0.0, 1.0, 1.0 RGB
+ (UIColor *)yellowColor; // 1.0, 1.0, 0.0 RGB
+ (UIColor *)magentaColor; // 1.0, 0.0, 1.0 RGB
+ (UIColor *)orangeColor; // 1.0, 0.5, 0.0 RGB
+ (UIColor *)purpleColor; // 0.5, 0.0, 0.5 RGB
+ (UIColor *)brownColor; // 0.6, 0.4, 0.2 RGB
+ (UIColor *)clearColor; // 0.0 white, 0.0 alpha
系统颜色
// System colors
@interface UIColor (UIColorSystemColors)
+ (UIColor *)lightTextColor __TVOS_PROHIBITED; // for a dark background
+ (UIColor *)darkTextColor __TVOS_PROHIBITED; // for a light background
+ (UIColor *)groupTableViewBackgroundColor __TVOS_PROHIBITED;
+ (UIColor *)viewFlipsideBackgroundColor NS_DEPRECATED_IOS(2_0, 7_0) __TVOS_PROHIBITED;
+ (UIColor *)scrollViewTexturedBackgroundColor NS_DEPRECATED_IOS(3_2, 7_0) __TVOS_PROHIBITED;
+ (UIColor *)underPageBackgroundColor NS_DEPRECATED_IOS(5_0, 7_0) __TVOS_PROHIBITED;
@end
获取颜色信息
