When creating a field style, consider what you would like to see as the actual style.
Service Now has a 'Basic' and 'Modern' field style. Below is an example of both, Left is Basic, Right is Modern:
This is a user preference: glide.ui.field_style_circles which OOB is set to true.
True shows the Modern Look
False shows the Basic Look
Users can set this individually by selecting the 'Modern Cell Coloring' option within the personalize column options modal.