We use Apple's built in GIF creation library, and unfortunately it skips some colors (for no good reason) and does not look as crisp as it should. Some animations export perfectly, while others have blurry text or are missing many colors.
Comfortable with the command line? Here's one way to get better detail out of your GIFs using a command-line tool.
Video --> Gif: Or, you could first Export as a Video (File > Export as Movie > MP4), and then import that video as frames to Photoshop. In Photoshop, you can select Window > Timeline to get fine-grained control over your Gif.
Mac Tools for Gif Capture
You could also directly record your screen using a tool like GIPHY Capture. You would just place the GIPHY capture window over your Tumult Hype document's preview. (We recommend Safari for best performance).
Licecap functions similarly. Download it 'here' and record the Safari browser playing your document.
Another solution is to drop that exported Video file into Gifrocket, a tool for turning videos into GIFs. GifRocket does a great job at maintaining colors from a video. Visit their site.
Can you confirm that you have added 'localhost' to your allowed domains to preview on your computer? (Follow these instructions).