By default, the platform does not have this option. You can use the following CSS code.
Please follow the steps below:
1. Go to BuddyBoss > Theme Options
2. Under Custom Codes, enable CSS
3. Append the following:
#buddypress a.button.outline, #buddypress a.button.outline:hover { background-color: #469482; color: #fff; border-color: #469482; }
4. Save changes.
Screenshots
Without Code
With Code