SharePoint App: Theming?

[Americo Perez]

Hi,

I have created a Communication site with some custom colors and font types and looks nice, but either the color or the font types are reflected in the SharePoint app. 

Even more, in Iphone the header of the site is like pink and in Android is blue, weird!

Is possible to style the SharePoint app in some way?

Best regards

Americo

[#2]

The same is true for our Hub and Associated sites. They should share a theme but instead each site is displayed with a different color banner in the app.