You can control many font or color elements for viewers on the web or in the mobile (iOS & Android) SDKs.
When using the web, any organization can customize the following elements from the "Themes" menu. Each theme applies to the web only, but it includes:
Right now, the color and font combinations can be configured in the SDK for most text elements. System UI elements used would not be affected by the themes you select.
There are the following options to configure:
Here is a figma doc that shows their usage throughout much of the application. Note that colors are not set by the font style, rather the colors used are those set in your color theme. For example, the HotMic SDK uses your primary, secondary, or desaturated colors in places in the app.
Both iOS and Android support light and dark mode.