Framework supports [themes](https://observablehq.com/framework/themes). You can define [custom themes](https://observablehq.com/framework/config#style). These set [colors](https://observablehq.com/framework/css/color) that can be used by Plot. Use the [brand guide](https://discord.com/channels/1097691936841801798/1208946530086682754/1210827567276490802) to figure out what colors to define. Maybe reference the [Missing middle](https://passbox.s3.ap-southeast-2.amazonaws.com/dwelling_maps/Heritage+and+zoning+in+Melbourne.html) report's CSS.