Instead of two colors, you could turn the half page devider off. So it will only be shown if the first half of the next page is showing. So you could easely tell if your gesture was working.
- Select display Mode -> turn off Show half page turn Position on all pages.
Samsung Galaxy Tab S7 FE Android 12
Samsung Note Pro 12.2 LineageOS 14.1
Huawei Media Pad M3 lite Android 7
Samsung Note Pro 12.2 LineageOS 14.1
Huawei Media Pad M3 lite Android 7