Congratulations and welcome!!
When the watch goes into a dimmed mode, after some time background watch face becomes slightly shadowed around the edges by black frame (you can see this on the photo).
Looks like orange is the colour of the day
No Dim https://www.dropbox.com/s/798xlhg5hqdx765/tag-heuer-24-ob.watch?dl=0
This is another version of the same Nanograph face, also based on a Brian Limomes and Anindya face:
This is the link for the WatchMaker app:
http://dk2dv4ezy246u.cloudfront.net/share/rkTAArwQN.watch
And this is the original watch: