coloring.acul.me has no CNAME records.
Question and response
Question
dig coloring.acul.me. NS
Answer
The response has no answer records.
Authority
acul.me. 1967 SOA ns11.infomaniak.ch. hostmaster.infomaniak.ch. 2026020502 10800 3600 605800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0