If Roll Film – Fixed Size for film scanning is chosen as the Auto Crop Method, Capture One CH will automatically estimate how successful the auto crop was for each image. This confidence feedback is indicted by three different Color Tags that is assigned to each variant.
A Green color tag means that there is a high probability of a successful auto-crop. Yellow indicates medium confidence that the auto crop was done correctly, while Red denotes low or very low confidence. Note that the primary image with Set Master Crop will be tagged with Blue color.
This feature is meant to make it easier and faster to review whether the auto cropping was done correctly. A useful workflow would be to filter the auto cropped variants by color tag. This is done by going to the main menu and selecting Edit -> Select By -> Color Tag and then either choosing Red, Yellow or Green.
The images with a high confidence level (Green) can then be reviewed fast with less scrutiny than those with a Red color tag. If fine-tuning is required, press the Auto Crop button again or adjust the crop manually with the Crop cursor.
Note that the assigned confidence levels are estimates, so it is entirely possible that an image with a Red color tag has been auto cropped correctly, while one with the Green tag could be improved upon.
NOTE: In case of significant frame changes, cropped variants will likely result in medium confidence crops (Yellow tag). The number of yellow tags can be greatly reduced if a new primary crop is set whenever film size changes significantly.