In the Theme Styles? Not at all. This will cause you problems at the latest when the theme style colors are gone. Therefore I would recommend you to work with classes instead, which is the most bulletproof solution, and you have full control over it (now and in the future).
For example (written as regular CSS, but you can easily create these classes with Bicks):
.btn { ... contains general styling as e.g. padding... }
.btn-rounded { ... contains your border-radius... }
.btn-muted { ...contains the muted background-color / color }
.btn-primary { ...contains the primary background-color / color }
…
Best regards,
timmse