The Thue-Morse and Rudin-Shapiro sequences at primes in principal number fields

We consider a numeration system in the ring of integers ${\mathcal{O}}_K$ of a number field, which we assume to be principal. We prove that the property of being a prime in ${\mathcal{O}}_K$ is decorrelated from two fundamental examples of automatic sequences relative to the chosen numeration system: the Thue-Morse and the Rudin-Shapiro sequences. This is an analogue, in ${\mathcal{O}}_K$, of results of Mauduit-Rivat which were concerned with the case $K=\mathbb{Q}$.