Thank you for including the sample images – it is very helpful to see what you are seeing.
The simplest first step to try would be to reduce the brightness setting for the capture. We have also found that there are some big differences in the way that computers handle HDMI output to the PiCapture “emulated monitor”. Adjusting the “gamma” setting can help a lot. Some graphics drivers can handle this directly, but a useful utility is “QuickGamma” for making changes easily and on the fly: QuickGamma (https://quickgamma.de/indexen.html)
Please let us know if that helps with the issue.