Storyline project borders in Rise

Hi everyone,

I am adding a Storyline project into a block in Rise. The client has requested a dark theme for this module. Even though Rise does not have an official dark theme, I am doing the best i can with what I have to work with.  I needed the Stroyline project to integrate itself into the Rise layout as seamlessly as posisble, so I set all of the Storyline project borders to match the color scheme of the block.

However, I'm noting little white spots on all four corners. I know that Storyline's player is a rounded rectangle, so I understand what is happening, but I would like to know if there is a way to change this white portion of the background so that it is the same color as the Storyline project border and the Rise block background. I've set the page background to also be the same grey color as the Rise block background.

I have included images of what my Rise block looks like, as well as the color settings for the Storyline player. Any help will be greatly appreciated.