Currencies

Currencies are created in Opencart > System > Localisation > Currencies. For more info see: Opencart Currency Documentation

To disable all currencies in your store just delete or disable all currencies except the one you use in your store.

Journal Currency Options

Currency styling options are in the Language/Currency style found in Journal > Styles > Language/Currency.

The styles are applied in the header modules in Journal > Header > Active Header > Language/Currency.