Updating 7 Powerpoint Presentations

I have 3 Powerpoint presentations which need a new colour scheme and professionally updating, the content is fine as it is, I just need them to look better and to be unbranded (please remove all the current branding - some may need removing from the master slide).

The presentation sizes are:

Presentation 1 - 5 slides.
Presentation 2 - 27 slides.
Presentation 3 - 30 slides.
Presentation 4 - 31 slides
Presentation 5 - 26 slides
Presentation 6 - 33 slides
Presentation 7 - 22 slides

There is nothing wrong with the slides, I just want them to look more eye-catching and professional, without any branding so I can use them for any clients I work with. I'd also like to be able to add further slides myself if I need to, and add in notes etc.

Ideally, I'd like these back by Sunday 4 September 2022.