You can notice this issue it when eg. adding a picture to a drop zone - it changes colors compared to its preview. This usually means that the user has changed project color science to managed in color management:
The solution is either revert back to default ‘DaVinci YRGB’ or adding a Gamut node to the preset in Fusion and playing with Source and Output Space. It can be saved for later too.
Here's a short video guide:
IMPORTANT NOTICE: The approach is slightly different when working with trackable callouts (eg. mCallouts Simple). In short, you need to use 2 Gamut Nodes: one before, and one after the callout, as on the screenshot below:
Make sure that Color Processing Mode is set to Auto/SDR: