When certain high-level events occur where the internet community wants to express protest, switching a website to show it's content on black is an often used measure.
Most of the time, some message will be displayed additional to the content (or instead of the content).
Therefore I like to propose the following be added to the banner feature: Turn the Tiki black.
It involves much labour to rebuild a CSS to reflect this. This could be automated. So flicking a switch on the banner feature might compile the previous CSS to one temporal CSS in which each and every colour gets inverted.
As most Tikis will render text mainly as mostly black letters on (kind of) white, such a colour reversal would automatically yield white on black, and even let contrast unchanged, so no areas that become hard to read will spring up.
And the deactivation is even easier to implement, simply go back to the original CSS.
Caches should be cleared after CSS manipulation, of course.
To help developers solve the bug, we kindly request that you demonstrate your bug on a show2.tiki.org instance. To start, simply select a version and click on "Create show2.tiki.org instance". Once the instance is ready (in a minute or two), as indicated in the status window below, you can then access that instance, login (the initial admin username/password is "admin") and configure the Tiki to demonstrate your bug. Priority will be given to bugs that have been demonstrated on show2.tiki.org.