Show customized colors for bootstrap element properties

Currently pinegrow seems to have a fixed color palette showing up for element properties of bootstrap elements. When customizing one or more of these colors (e.g. following Customize Bootstrap 4 themes), those changes are not reflected by the pinegrow UI for bootstrap element properties.

Specific example:
Let’s say one changes the primary color of the bootstrap theme-colors to violet following this tutorial: Customize Bootstrap 4 themes. Then the following screenshot shows what should occurr, but currently does not: