You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

jupyterlab-ca-theme
0.3.0

This version was deleted from PyPI around 2023-10-24. Installing fails with:
$ pip3 install jupyterlab-ca-theme==0.3.0 ERROR: Could not find a version that satisfies the requirement jupyterlab-ca-theme==0.3.0
View other deleted versions of jupyterlab-ca-theme

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2023-10-23/ \ jupyterlab-ca-theme==0.3.0
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
jupyterlab_ca_theme-0.3.0-py3-none-any.whl (31.4KB)
jupyterlab_ca_theme-0.3.0.tar.gz (106.4KB)