"Themis" is causing a colour shift in blue/indigo (EBU primaries?)

[whophd (Christian Kent)]

“Themis” is causing a colour shift in blue/indigo (EBU primaries?)

1. With two duplicate projects, one with, one without Themis, the Themis one has transformed some of the cobalt blue (saturated) hues into indigo, a little purple. The project is 1920x1080p50 into 4K50 with Apollo (6x) and Gaia HQ. It may be relevant that the source is Transfer Function “ITU-R BT.709” but with Colour Primaries “EBU Tech 3213” and YCbCr Matrix “ITU-R BT.601”, due to the 576i origin of the footage.

The correct result comes in the output file: *_apo8_ghq5.mov
The wrong result comes in the output file: *_thm2_apo8_ghq5.mov

2. Available on request but I need to know if it’s relevant before releasing; this is only a data issue.
3. Attached: logsForSupport.tar.gz
4. See four screenshots

[ida.topazlabs]

Thank you for sharing this, we have another case of this behavior. We currently believe that this is a bigger issue than just Themis. This color shift has also been noted with other models and we are looking into correcting this.

I added your screenshot to the current case and I will follow up with you on here as soon as there is additional information to share.