[UI] "Not free for all" block color hard to understand

[wargreen]

Steps to reproduce

1. Open popup to choose time slot
2. scroll to a date with many different status
3. try to choose the right time slot

Expected behavior

Colors are very helpful and directly understandable

Actual behaviour

The color for "not free for all" is very close to the other "busy" colors and not in the "?" menu. I've searched maybe 20 min before find the "free for all" function...

With dark theme :

With light theme :

Calendar app version

4.7.0

CalDAV-clients used

No response

Browser

Firefox 123.0.1

Client operating system

Debian sid

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

No response

Updated from an older installed version or fresh install

None

List of activated apps

No response

Nextcloud configuration

No response

Web server error log

No response

Log file

No response

Browser log

No response

Additional info

No response