A mix of the chandrian theme from https://github.com/narenranjit/chandrian-theme and the solarized colors https://ethanschoonover.com/solarized/.
IntelliJ IDEA theme code is based on 4lex4's Intellij Solarized themes for Intellij: https://github.com/4lex4/intellij-platform-solarized
Some of the colors are increased, so they have a contrast ratio of about 5:1, for readability, but also kept around 4.5:1 where necessary to keep the hue visible, making everything WCAG (AA) compliant, although a little higher contrast at times.
Let me know if the colors need improving in the reviews or open a github issue here) with requests!
There are three themes: black, dark blue, and tan version, with the color-hues preserved between them so the code doesn't change the feeling too much, as is part of the idea behind the solarized colors.
Available for both IntelliJ products and VSCode:
IntelliJ: https://plugins.jetbrains.com/plugin/20865-solarized-chandrian-themes
VSCode: https://marketplace.visualstudio.com/items?itemName=JackKenney.solarized-chandrian