They're candied pomelo peels. I made them! Covid-19 has changed my life in several ways. I've started to take a morning walk and take photos of plants I find during the walk. I've also started to cook something I didn't before because of a long time to cook, like jam or peels.
The peels are brownish orange because I always use brown sugar to sweeten food. I also eat brown rice and brown bread much more than white ones. Some say that brown food is healthier than white food, but that's not the reason I prefer brown food. I just like them. The thing is that it's difficult to find good rye bread at a reasonable price in Japan. I love a slice of rye bread with such peels and a black coffee!