Add backgroundColor support.

OLImageView.m

@@ -216,6 +216,12 @@ - (void)displayLayer:(CALayer *)layer
     layer.contents = (__bridge id)([[self.animatedImage.images objectAtIndex:self.currentFrameIndex] CGImage]);
 }
 
+- (void)setBackgroundColor:(UIColor *)backgroundColor
+{
+    [super setBackgroundColor:backgroundColor];
+    self.layer.backgroundColor = [backgroundColor CGColor];
+}
+
 - (void)didMoveToWindow
 {
     [super didMoveToWindow];

OLImageViewDemo/OLAppDelegate.m

@@ -50,6 +50,9 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
     [magicAnimatedVC.view addSubview:Aimv];
 
     Aimv = [[OLImageView alloc] initWithImage:[OLImage imageNamed:@"google-io"]];
+    Aimv.contentMode = UIViewContentModeCenter;
+    Aimv.clipsToBounds = YES;
+    Aimv.backgroundColor = [UIColor cyanColor];
     [Aimv setFrame:CGRectMake(0, 160, 160, 160)];
     [Aimv setUserInteractionEnabled:YES];
     [Aimv addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)]];
@@ -115,6 +118,8 @@ - (void)handleTap:(UITapGestureRecognizer *)gestRecon
         NSLog(@"STOP");
         [imageView stopAnimating];
     } else {
+        CGFloat randomHue = (CGFloat)arc4random_uniform(255) / 255;
+        imageView.backgroundColor = [UIColor colorWithHue:randomHue saturation:1 brightness:1 alpha:1];
         self.running = YES;
         NSLog(@"START");
         [imageView startAnimating];