I'm working on the Dutch translation for the program and therefore installed it to see where the texts are used for. In the Match the Colors sections you can mix colors by moving sliders on tubes of paint, so I'm told. I don't see sliders, I only see a plus and minus button to increase or decrease the amount of paint used.
Hi, yes we are using old Gtk+ version voices and some does not match. We should have used the status on https://l10n.kde.org/stats/gui/trunk-kf5/po/gcompris_voices.po/ to know which voice is up-to-date or not but I'm seeing Dutch is 100% so unfortunately it didn't work as expected. We will try to contact previous people who did voices to see if they can update them.
Thank you for reporting this issue in KDE software. As it has been a while since this issue was reported, can we please ask you to see if you can reproduce the issue with a recent software version? If you can reproduce the issue, please change the status to "REPORTED" when replying. Thank you!
After this bug was reported I've added back some sliders on the colors-mix activities, so this issue is not anymore. Closing as fixed :)