Use hex color string to add color in custom color palette (additionally to the RGB and HSL). Sure you can convert it but web based standard is Hex and in the XML it is saved in Hex anyway. (so why not enter it directly?)
Yes, like mentioned in the comments we do added this support. You will see this update on Office builds 12615.20000 or greater.
Thanks for submitting this idea.
Jamie Garroch commented
This is now available across all Office apps in the 365 release on 21st February 2020 - Version 2003 (Build 12615.20000).
Rick Engle commented
That would align it with other designer apps and make it much quicker to transcribe the same color between apps without having to convert each of the 3 HEX values to their RGB decimal equivalent:
I would love this - I'm currently working on 5 templates that have the same layout but wildly different colours; I only have a PDF to work from. I can grab HEX values via a desktop tool, but I can only enter them in as RGB one. value. at. a. time. What should be a quick copy/paste of a HEX value is a time consuming exercise fraught with potential for error.
When developing PowerPoint templates or Office Themes, we are usually given the Corporate Identity (CI) or Corporate Design (CD) guide of the company we work for. Most only use CMYK (for print) or HEX (for web). While conversion from CMYK always is inaccurate because the color space is different, conversion from HEX to RGB is possible but time-consuming. And why should we convert HEX to RGB, if it's converted back to HEX when PowerPoint saves the THMX file? This entry may not have many votes, as template design is not for the average user, but this feature would be helpful for template specialists.
This already exists on the mac version.
Chris Cochrun commented
100% agree. Many color palette tools on the web will just give you the hex numbers and then you either have to grab a picture of them and constantly use the eyedropper, or convert them to rgb. If we just use Hex, we'd be done.