Look in Synaptic for:
mate-themes
Official themes for the MATE desktop
This package contains the official desktop themes of the MATE desktop
environment.
The themes provided for the MATE desktop partially resemble themes that
are well known from GNOMEv2 desktops. However, the MATE team also prepared
some new themes esp. for MATE (Menta, GreenLaguna, TraditionalGreen,
TraditionalOk, and BlackMate).
Thank you. It works. Regards
Glad to help. I use TraditionalOK and have for years with no desire to change, so I understand you missing the Mate themes. Let's hope they keep them.
Please marked solved. The check mark under your last post.
I too like the Ambiant themes. I just copied it from the theme's folder in 20.04 over to the folder in 22.04 (user/share/themes). Works without any problem.
A trick I use: I have a usb which has my theme folder, background folder, Icons and firmware. Then, when I upgrade, if anything is missing, I can install it from the USB. Secondly, I update the USB adding any new items from a release or upgrade. Works great for the past few releases. Never broke anything.
Thanks. I did the same thing but copied them to a secondary hard drive and found there is a repository via ppa where you can download them from and install them in 22.04
This repository includes a variation of ambiant called Aqua. I don't know why it was removed but in matter of tastes nothing is written
sudo add-apt-repository ppa:lah7/ambiant-mate
sudo apt update
sudo apt install ambiant-mate-gtk-themes ambiant-mate-icon-themes
sudo apt install ambiant-mate-colours-aqua
Besides a new home for Ambiant-MATE, it is officially a community effort to keep maintained.
While the colours won't be conveniently installable via 
Welcome 22.04 onwards - the colours are still there via that PPA:
ambiant-mate-colours-aqua
-blue
-brown
-orange
-pink
-purple
-red
-teal
-yellow
If anyone wants to know more, here's information about the situation from the previously named ubuntu-mate-colours project:
Thank goodness.
I first tested the latest Ubuntu MATE on VirtualBox, and was totally put off by Yaru. No way I'd install it on any PC.
It's okay for devs to be smitten by Yaru and add it -- but it's outrageous to remove everything else for the rest of us.
Thank you very much for keeping Ambiant theme alive ! It's the best for me, I don't like Yaru.
Great community here, cheers !
My problem is that the window buttons in Yaru Mate are pixelated in HiDPI mode
Magnificent. A detail. There is a package that fails during installation and you need to run this command to fix it:
sudo dpkg-reconfigure libdvd-pkg
Yaru stinks. The icons are flat and have way less detail, hard to see, strains desktop vision. Thanks for keeping Ambient MATE in the community. Some things don't ever need to be changed for the sake of change.
Ooooau Lah7, thanks for the ppa
I just install the original Mate theme, so amazing, love it, so fantastic... just super
Maybe this theme and Mate Menu (Advanced Mate Menu) will return back in repository and be installed default on newer Os Releases ... this is the Original Ubuntu Mate Theme and should remain as a standard option.
With The Yaru theme I was thinking that maybe in future I will ditch Ubuntu Mate for Lubuntu but as long this theme exist I will no thave to even think on the option.
So happy that this classic theme still exist... thanks lah7
Same here
Went with the regular upgrade and and all my Traditional layout was preserved.
Happy
Change for sole purpose of changing brings nothing.
Thank you so much. I started vomiting after my upgrade from 20.04 to 22.04. - why do OS developers always think they have to destroy a user's handmade environment to make them believe that there's something innovative and new?
I agree, seems they would do better to fix bugs than create new themes. Then again these are creative people in general, so they want to create. As long a the old themes stay in the repository I am OK.
Dear Friends,
Drewing and jymm are one hunder percent correct.
I was so thrilled last night, the whole upgrade took thirty minutes, no issues, so I thought. Ready to donate.
Well, donations would be forthcoming if someone like lah or wimpress would simply have given the option:
Do you wish to keep your current customised theme - y for yes n for no - then press enter
I was thrilled that the upgrade took twenty minutes, instead of eight hours, bravo.
But why the hour to get my customisations back?
I live in the US and need the dollar sign more than euro or pound. So I need dconf to make the clock in the panel read 24h time? Ok, that is really unusual. Got it. But a theme?
Removing any file without asking is bizarre. So instead of thirty minutes, it would have been forty if asked to keep theme, or to keep hplip files or whatever. Still better than having to search for "where are my icons"?
The behaviour in my case was even more bizarre as some folders had the brown icons, and some emptyish text icons.
One possibility; a pay per month version for desktop users where the privilege of keepings one's settings and customisations is respected? or that the paid version allows tested versions of things that alphabet corp tries to make unavailable are made available sooner?
Lots of solutions, but creating another hour of searching because the devs implement change without asking seems an own goal.
So someone please provide a fail safe file copy to flash drive, and where it will go before april, please, because changing file location, buildings snaps, &c, seem to be the current mode, and it appears to be a fait accomplit
Best,
Martin
Hi @yazdzik,
your home directory seems like a safe place to keep your settings and customizations (including customized theme).
The only reason I switched from Ubuntu to Ubuntu Mate was because of the classic Ubuntu user-interface. I love Ubuntu Mate mainly for this reason, and I cannot believe the developers of Ubuntu Mate thought that switching to Yaru was the right move... A big thumbs down for this choice, sorry to say. At least provide both options so that people can decide.
On the other hand, thanks to this amazing community that is helping us get the best out of Ubuntu Mate and restoring the Ambient theme that many of us love.