If your company logo was designed by a professional designer chances are that somewhere in the bottom drawer of the marketing department you can find a complete graphical style guide that goes with it. Usually, it gets only used for commissioning other design work (brochures, web sites, etc.), and hardly any PowerPoint user knows of its existence.

Ask for a copy and use it to inspire your presentation design. See what colours the designer recommends, there might be more than present in the logo. See how pages are laid out. See what fonts and font colours are used. Lots of inspiration.

And yes, the section for the PowerPoint presentations in these style guides is usually pretty bad. Professional designers are not used to working in PowerPoint (an inferior product in their minds). Beautiful design work gets reduced to Arial, heavy top banners and watermarks. So, use the design inspiration of the first pages of the style guide to create your own PowerPoint template that fits it. Hopefully the marketing communications department lets you get away with it.