Changing the background color of the embedded Prezi Player using Prezi Player API / iframe

Hi folks!

At the moment I’m creating a website enriched with Prezis using Prezi Player API (https://prezi.github.io/prezi-player/lib/PreziPlayer/) . But obviously the Prezi Player that comes with an iframe element does not react to the window size. Therefore the black background color of the player is visible. This black does not match the intended website design (see below).

Is it possible to change this background color if necessary? E.g. adding a CSS style background-color:white will change the background color.

<div id="emscripten_container" class="webgl-viewer-container emscripten_container hidden-controls" tabindex="0" **style="background-color:white"**><canvas id="canvas" class="emscripten" width="1903" height="539" style="width: 1903px; height: 539px;"></canvas></div>

A JavaScript operation is unfortunately blocked due to a cross-domain request. The easiest way would be to allow cross-domain access for my domain tseidel.eu. Is this possible to change?

Could you tell me how I can easily change the background color of your Prezi player? This feature is necessary for my Prezi use case and it is what prompts me to buy a subscription. A purchase depends on this necessary option or feature.

Can someone else help me? I am open to any tip.

Cheers,
Tom