Bertie

Many thanks for you help !
I modofied the code to work in reverse:
 
.user-items-list-item-container[data-section-id="62ffdd571fe4027515d357c3"] li img { filter: grayscale(100%); } .user-items-list-item-container[data-section-id="62ffdd571fe4027515d357c3"] li:hover img { transition: 0.5s; filter: grayscale(0%); } .user-items-list-item-container[data-section-id="62ffdd571fe4027515d357c3"] .user-items-list-carousel__slide { pointer-events: initial !important; } The Transition property also makes it a little more elegant.
Cool and thank you for your time !

Hi,
Can you share link to page where you use carousel? We can check easier

Add to Design > Custom CSS
.user-items-list-item-container[data-section-id="62ffdd571fe4027515d357c3"] li:hover img { filter: grayscale(50%); } .user-items-list-item-container[data-section-id="62ffdd571fe4027515d357c3"] .user-items-list-carousel__slide { pointer-events: initial !important; }  

Media management is a basic entitlement if you ask me, especually for a content upload platform, how SquareSpace is now at its seventh itteration with minimal changes to this relationship with its customer base is a mystery to me.
Even now in 2022 I must use a hack just to get access to the media manager, only to find the selection option applies to a single file at a time i.e. if I want to delete on mass (which is the only function that I can see the selection option is there for, hastily bolted on by their design team under pressure) I must do so one at a time. It would be quicker to delete apps from a smartphone pressing and holding down on each one for a few seconds.
Media management is a core feature that everybody needs to visit at some point, it needs to be fully featured and quick to manage. I would even like it to sync directly with a local folder so that changes could be perrformed even quicker, but I suspect that is a little much to ask.
However, it's a lacking feature.

Plugin available
First letting anyone know, I've made a dark mode plugin for Squarespace which does exactly what you described.

coral background macbook toggling on off 1400px for blog.mp4 It also has automatic mode. It knows if user has dark mode in their phone/computer settings. It's not free, but if you have any problems I'll fix them. With free tutorials your emails won't get replied.
You can also read this blog post: Squarespace Dark Mode – Ultimate guide 
DIY
If you want to make one youreself, I recommend using the Squarespace 7.1 color palettes:

Basically creating a button, and that button will add a specific colour theme to all sections in the page. This way it's easy to edit how the dark mode should look, specifying each element and editing them easily.
Quite a bit of other customisations are needed as well. I can't share my entire plugin code (as it's something I've spent weeks on) but here's a video that tells exactly how it works and how a dark mode plugin can be made. It's pretty long and detailed. 
How a Squarespace dark mode plugin is coded (20 min video)
 
If that's too much, take a look at the Automatic dark mode plugin. Takes 1 minute to install. 
Here are some free tutorials: 
Dark Mode tutorial by Michael Henry
How to Add Dark Mode & Light Mode Toggle to your Squarespace Website by Squarestylist
This video goes to detail and is free. Video takes 15 minutes, has a lot of manual work. Some comments say it doesn’t work, doesn’t work on mobile and some places don’t turn dark...
 

Hi all,
I wanted to share a quick update that you can now select/delete/upload multiple images at the same time from your site's library. I understand the inability to do this was a pain-point so I hope this improvement helps out. 

Here's some more information about removing images from your site's library: 
https://support.squarespace.com/hc/en-us/articles/206542377-Managing-and-reusing-images#toc-delete-images-from-my-library

If you are on the Scheduling "Powerhouse Plan" then Scheduling elements can be styled with CSS but you'll need to be familiar with CSS or have assistance from someone who is. It is difficult to be more specific about what is and isn't possible without specific details, like URLs and confirmation you are on the "Powerhouse Plan".