The city of Chur kept a naturalization book from 1540. In this book, on page 32, in 1564, the following is noted: Gily Külch der Wyssgärber (Gili Kölen, Weisgerber) and his son Arnold are naturalized for 25+3 Gulden. Another source reports that from 1576 a Gili Köhl had sons and daughters in Chur. This could be confirmed in the baptism books from that time.
That Gili (Julius) gave his son the name Arnold is also an important indication of his origin, since often the name of the father (Arnold de Rogister) or grandfather was given to one of the older sons.
In a copy of the original baptismal book, made around 1660, as well as in the coat of arms letter of 1684, the name Julius is then used instead of Gili. Julius is a variant of the name Gili, Gilly or Gyly. But Gili could also have been the call name for Julius. In other entries the name Juli was also used instead of Gili.
Julius de Rogister changed not only his surname but also his given name before his naturalization. So Julius de Rogister became the white tanner Gili Külch and a short time later Gili Köl. For a better overview, the spelling Köhl is always used in the following.
As a citizen of Chur he could also become a member of a guild and had the right to a coat of arms. This coat of arms shows an Easter lamb carrying an Easter flag. This simple coat of arms was used until 1684 and can still be found on the doorway of a residential house at the Metzgertor as well as on three grave slabs in the city garden (Köhl family graves in the Chur city garden). According to the drawing by Johann Rudolf Amstein, the two colors blue/white were used early in the coat of arms
3: Sammlung Rätischer Geschlechter, Sprecher von Bernegg, Anton Hercules, 1847