How to change text color using Project css class

I am trying to change the text color in a label to the color described in a style in the Project CSS. The style is:

.emphasis {
font-weight: bold;
color: #FF0000;

I put emphasis in the Label property style. No change. Thoughts?

Is it a Common Label or a Bootstrap 4 Label?

Bootstrap 4 - but trying to make global changes, such as make the background color of all forms in the project blue, label text in all bootstrap4 labels red, etc.
The label above was Bootstrap4)

The idea of Bootstrap is that all your colors are controlled by the theme - and there are something like 20 different themes. Your app has a consistent look and feel if the same color palette is used throughout.

Bootstrap Label has a property called appearance, with 9 possible values. If you want to change the color of a label, the Bootstrap way would be to choose one of them.

If that’s not sufficient, the next step would be to override the theme. The proper way to do this would be to add css to Project CSS.

Got it. That begs another question - how do I change the theme to one I want to use? Does Appstudio just use Bootstrap themes like these?

Yes, in fact it uses those exact themes. You can select the one you want to use Project SettingsFrameworksBootstrapTheme

Thanks! It is under Frameworks in the Project Properties on a Mac.