Dear respected Angela,
As per the description, we understand your demand of using Combo Box in PowerPoint desktop app. But you would like to know how to add options using coding and also to color each option. If my understanding is correct, these can be achieved by using Macros. You may refer to: **** Creating a Drop-down List Box in PowerPoint: A Step-by-Step Guide - Solve Your Tech Please be aware that Microsoft provides no indicates to third-party links here and please protect your own privacy carefully.
Here is few references to color options:
Change font/format inside the options in the combo box for forms in - Microsoft Community
ComboBox control, AddItem method, Picture, PicturePosition properties example | Microsoft Learn
Though we would like to offer some more detailed support on macro coding, we are sorry to convey that moderators here mainly focus on out-of-box in PowerPoint application and have limited support experience on Macro and coding, so we sincerely recommend you go to the related community, which is the specific channel to handle such situation. See: Office VBA support and feedback | Microsoft Learn The engineers in related channel will focus on your specific scenario and provide complete guide on coding based on your scenario.
Please accept my Apologies for redirecting you to other channel as the moderators in this community have limited resources to support VBA macro coding, and to make sure you can get the fast and appropriate assistance we requested for it.
Feel free to come back with us if there have anything else I can do for you and we will offer the further support as much as we can. I appreciate your time and effort on checking these above and thank you for your patience and cooperation. I hope that you are keeping safe and well! Sincerely,Mia | Microsoft Community Moderator