If you're using a custom skin you can add a copy of the following
https://github.com/ILIAS-eLearning/ILIAS/blob/release_5-4/Services/Init/templates/default/tpl.login_registration_links.html
To your skin folder under Services/Init and give it an id or class for you to select on. You could even inline style it there if you wanted (though it'd be cleaner to add it to the less file.)
EG
<!-- BEGIN new_registration -->
<a style='do your inline styling here.' class="il_ContainerItemCommand" href="{CMD_REGISTER}">{REGISTER}</a>
<!-- END new_registration -->
<!-- BEGIN homelink -->
<a class="il_ContainerItemCommand" href="./index.php{CLIENT_ID}">{TXT_HOME}</a>
<!-- END homelink -->
<!-- BEGIN password_assistance -->
<a class="il_ContainerItemCommand" href="{CMD_FORGOT_PASSWORD}">{FORGOT_PASSWORD}</a>
<a class="il_ContainerItemCommand" href="{CMD_FORGOT_USERNAME}">{FORGOT_USERNAME}</a>
<!-- END password_assistance -->
<!-- BEGIN client_list -->
<a class="il_ContainerItemCommand" href="{CMD_CLIENT_LIST}">{TXT_CLIENT_LIST}</a>
<!-- END client_list -->