We've added a couple of new background transitions. They follow the same style as the main slide transitions so that they can be matched with one another. When the two transitions are matched, you end up with what looks like a full screen slide transition which is really nice.

Examples: https://slid.es/news/new-background-transitions/

Glad you like that idea. We'll be adding additional background transitions soon.

Yes please do file the CSS selector for backgrounds as separate request otherwise it might get burier and incorrectly closed here once the blank theme topic is addressed.

We'll make reveal.js mirror the "data-state" value from slide sections to their corresponding background. After that we'll need to figure out where it would make sense to define that state name through Slides.

That's a great idea.
Additionally however if the slide templates could also put a selector on the background element (only to be used by those who know it is there) then special custom background animations could be crafted with the CSS editor (only for those rare occasions).

Ideally, most uses would only need what's in the background transition gallery.
No doubt having a gallery like the codrops folks have here: http://tympanus.net/Development/PageTransitions/ would be an awesome addition

I think I've let this request go way off topic but thanks for entertaining these ideas.
slide templates and having selectors for custom background transitions matter a lot to the uses we're trying out. Should I put the selectors request in as another uservoice question so that this can stay dedicated to blank themes?

Regarding #3, that's an interesting use case.

Ideally we'd like to focus on exposing features through the interface so that they are accessible to more people, as opposed to requiring more in-depth knowledge about how reveal.js works. What do you think about us offering more types of background transitions and providing the ability for authors to specify different transitions per slide? reveal.js already supports this through data-background-transition.

With that, as well as a slide library, you could prepare slide templates that do what is shown in your example.

Let me know what you think.

I guess these are 3 separate requests:

1. full color picker = Excelent
2. Blank style theme option = also excellent

3. A UI to add selectors to slides (for linking background and foreground slides when writing CSS).
Similar to what setting an attribute for data-state="" on a <section> does when using revealjs

This way custom CSS can define global rules for background and foreground styles and transitions.
It means we can craft a custom theme globals with different styling control depending on the slides selector.

It might make sense to just add a field to the html editor that enters attributes to data-state, or something else.
The point is, what you'd want that field to create is a selector for bg and foregrounds.

So for example, If I wanted to define a style that would slowly zoom a background into view out and have the slide text only appear once the transtion was complete I could set the following.

<section data-state="zoom-teaser">

which would affect the background div like this
<div class="background zoom-teaser">

So now we can write custom code for both the background and the foreground using .backgrounds div.zoom-teaser {} and .slides .zoom-teaser{}

A mock of the functionality is demonstrated here:

http://slid.es/redhat/demo-on-the-next-slide?token=oZsS6kUru4qarSEWxtxxzpwA27Yr

but right now it has to use nth-child() selectors to define the link between backgrounds and foregrounds. It's a bit of a hack and doesnt allow easy nomination of a slide style.

Thoughts ?

Thanks for the feedback. We'll see what we can do about this in the theme editor, at least having a "none" style for colors and fonts would be a useful addition.

In your second comment, are you referring to the background color picker? Not sure if classes make sense there. We have considered replacing that UI with a normal color picker and if we do it won't be possible to have preset names for the colors.