Black windows of calendar and contact

Hello,
I am new to this forum.
I need a help.
The windows’ color of calendar and contact are black as default after system installation.
Then I changed the theme to Radiance but the color of the windows of calendar and contact remain black.
I would like to change it into the default Radiance color.
How can I do this?
Thank in advance for your answers.

Jusuf.

Did you try to log out and back in again after changing the theme? Sometimes it’s needed to do so.
If that doesn’t work feel free to file a bug report at Gitlab and mention which version of Ubuntu Unity you are using. Issues · Ubuntu Unity / ubuntu-unity-issue-tracker · GitLab

Thanks Malk for your answer.
I have just tried to reboot the system but nothing has changed.

I will find another solution.