The following is how to customize primary tags inside your Roam graph. I classify primary tags as tags in ‘heavy use’ or ‘recurring’ frequently. And in following Roam’s webbed-thinking framework, it is likely that a document will have many tags and links. Customizing a primary tag to stand out from the rest is visually beneficial.
Layout
Red Gregory's Roam Research CSS Themes
The following are a couple Roam CSS themes I’ve made recently. Included is a light mode theme, and another in dark mode. I utilize custom tags of which are the same in each template: #Area, #Subtask, #Urgent, #Inbox, #Thought, #Timeline, #Person, #Consideration, #Editlater, #Morning, #Evening, #Quicktask.