We will shortly be deploying the Microsoft Teams App Company Communicator with custom colour and outline icons. https://github.com/OfficeDev/microsoft-teams-apps-company-communicator/wiki
Under the requirements for the outline icon, it says it can only be "white with a transparent background or transparent with a white background (no other colours are permitted"). This isn't an issue in dark mode but in standard white mode surely the icon will not appear against the white sidebar? Any clarification on this would be appriciated.