I hesitate (have been hesitating actually) to mention this because I know how welcome a thing it is to troubleshoot color issues. :p
Hopefully this should be reproducible.
Import any video (I mostly work with h264 mp4), then output via Vapoursynth to RAW/PNG. Compare a source frame to the same output PNG frame. You should notice a color shift (which shouldn't happen). What I usually do to compare: load the source mp4 in VirtualDub. Go to the frame you're comparing. Video --> Copy source frame to clipboard. Go into IrfanView, Edit --> Paste. Then start another instance of IfranView, "File" --> "Open" and then navigate into the folder where you output PNG files in Hybrid, and select the PNG for the same frame (add one, since Hybrid starts export at frame number 1 instead of frame number 0). Click between the two IrfanView windows via the start bar to easily compare differences. (I have View --> Display Options --> Fit only big images to window selected in IrfanView.)
Right now, the fix/workaround is to set the ColorMatrix filter in Hybrid on the Vapoursynth --> Color --> Matrix tab in Hybrid: "From" to "Rec.709" and "To" to "Rec.601/470bg/470m". (Clear "Adjust by resolution" tick box and leave "pre and post clipping" enabled.)
If you do the same export with the above filter enabled, the exported images will now match when you compare them.
Hopefully this should be reproducible.
Import any video (I mostly work with h264 mp4), then output via Vapoursynth to RAW/PNG. Compare a source frame to the same output PNG frame. You should notice a color shift (which shouldn't happen). What I usually do to compare: load the source mp4 in VirtualDub. Go to the frame you're comparing. Video --> Copy source frame to clipboard. Go into IrfanView, Edit --> Paste. Then start another instance of IfranView, "File" --> "Open" and then navigate into the folder where you output PNG files in Hybrid, and select the PNG for the same frame (add one, since Hybrid starts export at frame number 1 instead of frame number 0). Click between the two IrfanView windows via the start bar to easily compare differences. (I have View --> Display Options --> Fit only big images to window selected in IrfanView.)
Right now, the fix/workaround is to set the ColorMatrix filter in Hybrid on the Vapoursynth --> Color --> Matrix tab in Hybrid: "From" to "Rec.709" and "To" to "Rec.601/470bg/470m". (Clear "Adjust by resolution" tick box and leave "pre and post clipping" enabled.)
clip = core.resize.Spline36(clip=clip, matrix_in_s="709", matrix_s="470bg", range_in=0, range=0)If you do the same export with the above filter enabled, the exported images will now match when you compare them.