If you're doing WPF, point JetBrains DotPeek (free!) at AdUiPalettes.dll and look under the Resources \ palettes \ all the .bamls which will decompile into XAMLs. There may be other DLLs with theme stuff in them. For amusement, run a debug session on an AutoCAD plugin and turn WPF binding errors on - AutoCAD 2019 has quite a few without any help from me.