The following should work:
+ (UIImage *)blankUIImageOfSize:(CGSize)size {
UIGraphicsBeginImageContextWithOptions(size, NO, 1);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextClearRect(ctx, CGRectMake(0, 0, area.width, area.height));
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}