XCodeのUnitTestで、Failを赤く表示する ref: http://qiita.com/items/e0be611627e38835aa74

file1.m

    STFail(@"Unit tests are not implemented yet in PAMColorUnitTestTests");

SenTestCase+PAMColor.h

//
//  SenTestCase+PAMColor.m
//  PAMColorUnitTest
//
//  Created by 田村 孝文 on 2013/01/27.
//  Copyright (c) 2013年 田村 孝文. All rights reserved.
//

#import "SenTestCase+PAMColor.h"
#import <objc/runtime.h>

// NSProxy 参考
// http://d.hatena.ne.jp/Kazzz/20120205/p1
@interface PAMColorExceptionProxy : NSProxy
@property(nonatomic,strong) NSException *targetException;
@end

@implementation PAMColorExceptionProxy
@synthesize targetException;

// "色付き"の文言を返す
- (NSString *)reason
{
    return [NSString stringWithFormat:@"\033[fg255,0,0;%@\033[;",
            self.targetException.reason];
}

- (void)forwardInvocation:(NSInvocation *)invocation
{
    if ( self.targetException )
    {
        [invocation setTarget:self.targetException];
        [invocation invoke];
    }
}
- (NSMethodSignature *)methodSignatureForSelector:(SEL)sel
{
    NSMethodSignature *result;
    if ( self.targetException )
    {
        result = [self.targetException methodSignatureForSelector:sel];
    }
    else
    {
        result = [super methodSignatureForSelector:sel];
    }    
    return result;
}
@end

@implementation SenTestCase (PAMColor)
+(void)load
{
    // failWithexceptionメソッドを入れ替える
    SEL originalSelector = @selector(failWithException:);
    SEL overrideSelector = @selector(swizz_failWithException:);

    Class clazz = [self class];
    Method originalMethod = class_getInstanceMethod(clazz, originalSelector);
    Method overrideMethod = class_getInstanceMethod(clazz, overrideSelector);

    method_exchangeImplementations(originalMethod, overrideMethod);
}

-(void)swizz_failWithException:(NSException *)exception
{
    // Proxyでラッピング
    PAMColorExceptionProxy *e = [PAMColorExceptionProxy alloc];
    e.targetException = exception;

    // method_exchangeImplementationsで「入れ替わってる」ので、
    // ↓でオリジナルメソッドを呼び出す
    [self swizz_failWithException:(NSException *)e];
}
@end