Storyline "Next" Button - How to Make Larger?

Hi,

Does anyone know of a way to make the Next button on the Storyline player larger so it stands out better? Right now, it seems really small. I have been trying different color combinations on the player and have kept the Next button hidden until the voiceover finishes to make it stand out, but it isn't really helping. I really just want to make the Next navigation icon larger on the player, but there doesn't seem to be a way to do that.

I don't want to add a voiceover or text that says "Click Next to Continue" on every slide. I also don't want to put custom navigation buttons on each slide because they would cover some of the content if someone wants to review before moving to the next slide. 

Thanks, 

Melanie