How to change the designe of all slides after they have been created?

Hi,

I thought this was trivial but I can’t figure it out. I created a bunch of slides in a presentation and I want to change the design (colors, mostly). How to I change it in one slide and have it update all the slides? I’m using a three page template (one for title, one for text content, one for mostly images). How do I make so when I change the text content slide, every slide that uses that same master slide format gets updated?

Thanks,

L

P.S. I’m on 7.4