There are 2 repositories under logitech-rgb-keyboard topic.
This is a C# program using Logitech LED SDK. It can set your device's LED color and it can cycle smoothly through two colors instead of three provided in the LGS. For example: Blue to magenta, magenta to red, red to magenta, magenta to blue. Repeat.
A simple Windows application that renders audio data on your Logitech RGB keyboard
Manual profile selection and creation utility for the Logitech G810 mechanical keyboard.
Display various system states using keyboard LED colours. This fork adds support for Corsair RGB keyboards and retrieving build status info from Azure DevOps. The network interface monitor has also been extended for configurability.