Changing layer style for a single record or all records (video)
The color of a layer can be changed from within a record by expanding the layers panel and clicking the point, line, or area swatch next to the layer you want to change. You can also change point size, line style (solid/dashed/dotted) and weight, area perimeter style and weight and area fill. Changes to style are seen by all users.
Here's a quick video on how to change that for a single record. Edits made in this way will not affect other records: