My old CLI program, but improved and converted into a .NET library for general usage.
Available in NuGet! https://www.nuget.org/packages/FlagPFP.Core/
The package will be added to the Github Package Registry soon.
The source code contains XML documentation that can aid you in development. If you still need a reference while I implement proper documentation to this repository, check out this repository.
The repository linked above also has an example folder with pretty much all pride flags I could find. Feel free to use them, of course!