Perhaps you both use different versions of DBP that has you confused, I just quickly tried u7.7rc7 and u 7.62 and both failed to show the assigned vertex diffuse colours but with version u7.1 it showed up just fine
so just a simple matter of checking which versions it works with and which of those working versions are best for you.
I simply install the original dbp, copy it and add "original" at end of folder name then copy it, remove the "copy of original" wording(or similar wording) then install an upgrade, rename the folder but this time just tag the u X.X version at the end, make another copy of the original folder then repeat the process for each upgrade you wanna test. This way all you have to do is rename the folder each time you wanna switch between versions(might be best to keep a .txt file with details of what the current version is installed as you switch between them which is what I do).
Seasonal Greetings