Seems like the beta link leads to the Release version.
I used the beta64 download link.
I installed to a unique directory: \Program Files\ParkControl-beta\
It has the exact same dark navy blue UI.
About ParkControl Pro:
ParkControl v5.5.2.11
The current ParkControl beta version was only incremented in the least significant digit because it is, so far, a very inconsequential (translations) update.
Final: v5.5.2.8
Beta: v5.5.2.11
I can see how this could be confusing and we'll go ahead and advance to v5.5.3 beta in the next build.
Thank you