Having fun everyone. I wish you are all doing good in this tough time.
It was Adolfo who complaint about Colibre's failure to accomplish WCAG contrast guideline. He said the colors are too faint and everything looks washed out. Furthermore, MS Office 365 has since moved those colors to a brand new monoline style iconography. See this bug report for details
So I took the chance to update this Windows default icon theme. Luckily, the icon theme comes with SVG version, I can easily use bash script to automate a neccessary color conversion, and take the rest manually. In one month, I finally managed to finish this "Neo" Colibre. Hopefully this will benefit the largest LibreOffice user platform (approximately more than ~80%).
Here you can see side by side comparison to see the improvement (click to enlarge then right click > "View Image" for Firefox, right click > "Open image in a new tab" for Chrome for maximum appearance)
Start Center
Standard User Interface
Writer
Calc
Impress
Math
Draw
Base
Tabbed User Interface
Writer
Calc
Impress
Draw
Objects
Image
Table
Chart
3D Settings
By God will, this will be available in 7.0 release. You can try it earlier from my github repo as an extension (make sure your LibO version equal or greater than 6.0):