I've been having consistent issues with my Brand Colors not loading in Express. They are available in Adobe Creative Cloud (mac desktop app).
Additionally, there are some general inconsistencies with Express webapp vs. CC app. In CC I can upload assets and organize them into folders. When I go into Express, they are auto-sorted into Overview, Logos, Colors, Fonts, Templates, Assets or Other. Even if this is an intended limitations with Express (for some reason?) I'm guessing its only going to bug out the system/files overtime if Creative Cloud is permitting us to create new folders and move the assets into them. But in this particular case, these missing colors are in the default "Colors" group.