Creates a SKTexture programatically with a vertical gradient.

SKTexture+Gradient.h

#import <SpriteKit/SpriteKit.h>

@interface SKTexture (Gradient)

/** Creates a SKTexture programatically with a vertical gradient.
 
 Great suggestion for colors: http://ios7colors.com/.
 
 Example:
 (Inside a SKScene class)
  CIColor *topColor = [CIColor colorWithRed:1 green:0.369 blue:0.227 alpha:1];
  CIColor *bottomColor = [CIColor colorWithRed:1 green:0.165 blue:0.408 alpha:1];
  SKTexture* backgroundTexture = [SKTexture textureWithVerticalGradientofSize:self.size
                                                                     topColor:topColor
                                                                  bottomColor:bottomColor];
  SKSpriteNode* backgroundGradient = [[SKSpriteNode alloc] initWithTexture:backgroundTexture];
  backgroundGradient.position = CGPointMake(self.size.width/2, self.size.height/2);
  [self addChild:backgroundGradient];
 */
+(SKTexture*)textureWithVerticalGradientofSize:(CGSize)size
                                      topColor:(CIColor*)topColor
                                   bottomColor:(CIColor*)bottomColor;

@end

SKTexture+Gradient.m

#import "SKTexture+Gradient.h"

@implementation SKTexture (Gradient)

+(SKTexture*)textureWithVerticalGradientofSize:(CGSize)size
                                      topColor:(CIColor*)topColor
                                   bottomColor:(CIColor*)bottomColor
{
    CIContext *coreImageContext = [CIContext contextWithOptions:nil];
    CIFilter *gradientFilter = [CIFilter filterWithName:@"CILinearGradient"];
    [gradientFilter setDefaults];
    CIVector *startVector = [CIVector vectorWithX:size.width/2 Y:0];
    CIVector *endVector = [CIVector vectorWithX:size.width/2 Y:size.height];
    [gradientFilter setValue:startVector forKey:@"inputPoint0"];
    [gradientFilter setValue:endVector forKey:@"inputPoint1"];
    [gradientFilter setValue:bottomColor forKey:@"inputColor0"];
    [gradientFilter setValue:topColor forKey:@"inputColor1"];
    CGImageRef cgimg = [coreImageContext createCGImage:[gradientFilter outputImage]
                                              fromRect:CGRectMake(0, 0, size.width, size.height)];
    return [SKTexture textureWithImage:[UIImage imageWithCGImage:cgimg]];
}

@end

Thanks for this class, while using it on a iPad II and iPhone 4S i get this error: "BSXPCMessage received error for message: Connection interrupted"

Thanks for this! I've added gradient directions and converted to Swift here:
https://gist.github.com/craiggrummitt/ad855e358004b5480960

Dont forget to #import <CoreImage/CoreImage.h>