message: [Media Preview] Artsy purple progress indicator.
diff: #import "ARMediaPreviewController.h"
  +#import <Artsy+UIColors/UIColor+ArtsyColors.h>
  +
  @import MobileCoreServices;
  @import QuickLook;
  @import ObjectiveC;
  @@ -56,6 +58,7 @@ static char kARMediaPreviewControllerAssociatedObject;
  {
  dispatch_async(dispatch_get_main_queue(), ^{
  UIProgressView *progressView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
  + progressView.tintColor = [UIColor artsyPurpleRegular];
  self.progressView = progressView;
  CGRect frame = progressView.bounds;
  frame.size.width = CGRectGetWidth(self.originatingView.bounds);
  