Out of the box, Polotno does not support the rendering of rich text elements, meaning you cannot apply different styles, colors, fonts, etc., to parts of the text. The entire text element must maintain a uniform style. However, Polotno offers support for rich text elements, which must be explicitly activated.
How to enable rich text support?
When 'html renderer' is enabled, Polotno will use very different rendering logic for text elements. Rich text may drop the performance of your application if you have many text elements. Please report any issues you may come across.
Polotno has many clients who use these settings on production. The feature considered as stable and supported. The "unstable" prefix will be removed soon.
If you use Cloud Render API, please make sure to pass htmlTextRenderEnabled: true to enable rich mode.