UIColor

// rgb颜色转换（16进制->10进制）
#define UIColorFromRGB(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]

hex颜色设置

+(UIColor *)colorWithHexString:(NSString *)hexString alpha:(CGFloat)alphaValue
{
    NSString *colorString = [[hexString stringByReplacingOccurrencesOfString: @"#" withString: @""] uppercaseString];
    CGFloat alpha, red, blue, green;
    switch ([colorString length]) {
        case 3: // #RGB
            alpha = 1.0f;
            red   = [self colorComponentFrom: colorString start: 0 length: 1];
            green = [self colorComponentFrom: colorString start: 1 length: 1];
            blue  = [self colorComponentFrom: colorString start: 2 length: 1];
            break;
        case 4: // #ARGB
            alpha = [self colorComponentFrom: colorString start: 0 length: 1];
            red   = [self colorComponentFrom: colorString start: 1 length: 1];
            green = [self colorComponentFrom: colorString start: 2 length: 1];
            blue  = [self colorComponentFrom: colorString start: 3 length: 1];
            break;
        case 6: // #RRGGBB
            alpha = 1.0f;
            red   = [self colorComponentFrom: colorString start: 0 length: 2];
            green = [self colorComponentFrom: colorString start: 2 length: 2];
            blue  = [self colorComponentFrom: colorString start: 4 length: 2];
            break;
        case 8: // #AARRGGBB
            alpha = [self colorComponentFrom: colorString start: 0 length: 2];
            red   = [self colorComponentFrom: colorString start: 2 length: 2];
            green = [self colorComponentFrom: colorString start: 4 length: 2];
            blue  = [self colorComponentFrom: colorString start: 6 length: 2];
            break;
        default:
            blue=0;
            green=0;
            red=0;
            alpha=0;
            break;
    }
    return [UIColor colorWithRed: red green: green blue: blue alpha: alphaValue];
}
+(CGFloat)colorComponentFrom:(NSString *)string start:(NSUInteger)start length:(NSUInteger)length
{
    NSString *substring = [string substringWithRange: NSMakeRange(start, length)];
    NSString *fullHex = length == 2 ? substring : [NSString stringWithFormat: @"%@%@", substring, substring];
    unsigned hexComponent;
    [[NSScanner scannerWithString: fullHex] scanHexInt: &hexComponent];
    return hexComponent / 255.0;
}

//16进制色值转换

#define UIColorFromHex(hex) [UIColor colorWithRed:((float)((hex & 0xFF0000) >> 16))/255.0 green:((float)((hex & 0xFF00) >> 8))/255.0 blue:((float)(hex & 0xFF))/255.0 alpha:1.0]

.h文件
#import <UIKit/UIKit.h>

@interface UIColor (Hex)
/**
 @param hexString   NSString e.g:@"0xFC5B13"
 @param alpha  alhpa
 */
+ (instancetype)colorWithHexString:(NSString *)hexString alpha:(CGFloat)alpha;
+ (instancetype)colorWithHexString:(NSString *)hexString;

@end

.m文件
#import "UIColor+Hex.h"

@implementation UIColor (Hex)

+ (instancetype)colorWithHex:(int)hexNumber alpha:(CGFloat)alpha{
    
    if (hexNumber > 0xFFFFFF) return nil;
    
    CGFloat red   = ((hexNumber >> 16) & 0xFF) / 255.0;
    CGFloat green = ((hexNumber >> 8) & 0xFF) / 255.0;
    CGFloat blue  = (hexNumber & 0xFF) / 255.0;
    
    UIColor *color = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
    
    return color;
    
}

+ (instancetype)colorWithHexString:(NSString *)hexString alpha:(CGFloat)alpha{
    
    hexString = [[hexString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    
    UIColor *defaultColor = [UIColor clearColor];
    
    if (hexString.length < 6) return defaultColor;
    if ([hexString hasPrefix:@"#"]) hexString = [hexString substringFromIndex:1];
    if ([hexString hasPrefix:@"0X"]) hexString = [hexString substringFromIndex:2];
    if (hexString.length != 6) return defaultColor;
    
    //method1
    NSScanner *scanner = [NSScanner scannerWithString:hexString];
    unsigned int hexNumber;
    if (![scanner scanHexInt:&hexNumber]) return defaultColor;
    
    //method2
    const char *char_str = [hexString cStringUsingEncoding:NSASCIIStringEncoding];
    int hexNum;
    sscanf(char_str, "%x", &hexNum);
    
    return [UIColor colorWithHex:hexNumber alpha:alpha];
}

+ (instancetype)colorWithHexString:(NSString *)hexString{
    return [UIColor colorWithHexString:hexString alpha:1.0f];
}