How to restore my colors/theme?

It would appear, as I became convinced with PyCharm a few weeks ago, that there is no way to restore the original chromatic appearances of IDEA. Finding a theme close to your old one is about the only option, then get busy with Editor → Color Scheme.

I would have preferred the update present the option to preserve what was there.

According to users' requests, some of our themes were not contrasting enough, or the contrast was too high. Therefore, we keep changing some colors. If you would rather keep an old version, please let us know the theme name, and the version number. We will send you the custom theme with the saved colors, and the custom theme is not subject to change during version upgrades. 

I think my problem is that, when I began using IntelliJ IDEA over a decade ago and established the (few, mostly “wheat” colored text-edit panes I wanted), there were no themes yet. I was just shocked that upgrading meant that I was suddenly imposed a dark theme. I have “started over” by setting IntelliJ Light and I may choose to change my edit views to a wheat color or not. We'll see.

Thanks!

Could you please return intelligent light theme?

IntelliJ Light theme is a part of Classic UI

Is it possible to have the IntelliJ Light theme in the new UI?

That is what I'm using.

IntelliJ IDEA 2024.1.2 (Ultimate Edition)
Build #IU-241.17011.79, built on May 21, 2024
Licensed to Russell Bateman
You have a perpetual fallback license for this version.
Subscription is active until May 31, 2025.
Runtime version: 17.0.11+1-b1207.24 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Linux 5.4.0-182-generic
GC: G1 Young Generation, G1 Old Generation
Memory: 4096M
Cores: 16
Non-Bundled Plugins:
 io.gitlab.zlamalp.arc-theme-idea (2.0)
 zielu.cleansheet (211.4.0)
 com.github.adamwojszczyk.sepiaTheme (0.15.0)
 light.flat.theme (0.14)
 shirotelinintellij.yasukotelin.com.github (1.9.1)
 com.intellij.ideolog (222.3.2.0)
 com.jetbrains.grayTheme (1.3)
 Eclipse theme (1.0)
 com.intellij.kubernetes (241.17011.162)
 com.jetbrains.packagesearch.intellij-plugin (241.0.11)
 com.firsttimeinforever.intellij.pdf.viewer.intellij-pdf-viewer (0.15.0)
Kotlin: 241.17011.79-IJ
Current Desktop: X-Cinnamon

Mine:

PhpStorm 2024.1.2
Build #PS-241.17011.119, built on May 28, 2024
Subscription is active until October 6, 2024.
Runtime version: 17.0.11+1-b1207.24 aarch64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
macOS 14.5
GC: G1 Young Generation, G1 Old Generation
Memory: 4096M
Cores: 12
Metal Rendering is ON
Registry:
 run.processes.with.pty=TRUE
 ide.experimental.ui=true
Non-Bundled Plugins:
 com.jetbrains.space (241.17011.48)
 dev.meanmail.plugin.nginx-intellij-plugin (2024.3)
 com.intellij.laf.macos (241.14494.150)
 com.intellij.ml.llm (241.17011.2)
 com.kalessil.phpStorm.phpInspectionsEA (5.0.0.0)
 com.xu (1.3)
 de.espend.idea.php.annotation (10.0.0)
 com.kalessil.phpStorm.yii2inspections (1.0.6)

 Is it possible to have the IntelliJ Light theme in the new UI?

Try “Light with light header” theme

Thank you, but it's a little bit not the same as IntelliJ Light