Good day,
I suppose you have extracted the We.The.People.2.8.zip or .rar to ..\Documents\My Games\Civilization IV Colonization\MODS
And if you open the only folder in 'MODS' which might be 'We.The.People.2.8' (could be named differently for you but will probably be the only folder in there)
I think I had a problem getting it to load in the past by starting the game and going to 'load a mod'.
I had to open the file ..\Documents\My Games\Civilization IV Colonization\ CivilizationIV.ini (which is 2nd from the bottom) scroll down to the middle of the file where it says:
; Specify a Mod folder (Mods\Mesopotamia), '0' for none
Then change the next line to:
Mod = Mods\We.The.People.2.8 (if We.The.People.2.8 is the name of the folder that holds the folders Assets, Project Files, Public Maps etc, otherwise change it to whatever it is named for you.)
or maybe
Mod = Mods\We.The.People.2.8\We.The.People.2.8\if you accidentally created too many folders
Save the file, exit and start the game and see what happens.