Using Nuke is a little overwhelming at first, but in this video, I cover getting a mask to disk, using the Rotobot_InstanceSegmentation node, followed by Shuffle and then Write. This has been calculated for a sequence in advance of this video, but one frame is calculated live. The mask is then brought back in via a Read node, the alpha channel is then inverted using an Invert Node, to allow a Multiply Node to change the colour of the background.
The video is lengthy, allow 2 minutes with fast forwarding, or 6 minutes with patience listening to my dialog about how it works and what to expect. This is updated, we bring in the footage, switch to Fusion, create the Robotbot_Segmentation node, followed by a ChannelBoolean to copy the red channel to the alpha, create a Saver.. then preview the result on the ChannelBoolean, before saving the sequence to disk.
Demonstrating the same thing is possible on Windows 10, using the Fusion Module for Resolve.
A few colour grading folk on social media were curious if Rotobot OpenFX Plugin works out of the box on DaVinci Resolve. I did the same thing under Windows 10 earlier in the day, but here is a recording of me putting Rotobot through its paces on a MacBook Pro under macOS 10.12 using Resolve