Surprisingly few organisations have a proper style guide with instructions for logos, colours, fonts, etc. This is always the first thing I ask for when starting a new presentation design project. As a presentation designer, I need the colours most.
If your organisation does not have one, here is a great tool to create your own: Frontify. You can start with a logo image, extract the colours from it, and take it from there.
SlideMagic: a platform for magical presentations. Free student plan available.