Okay so I used to watch this TV show probably sometime between 2005 and 2012, I'm not really sure when though. The show combined live action and animation and I believe it aired on CW4Kids on weekends.
When the main characters were at school and with their families, the show was live action, but then they would have to go and fight these monster things (or maybe it was large insects?), so they would pass through a mall photo booth and the show would become completely animated, they were in maybe a game world or a sewer system or a computer circuit board or a maze? Not really sure what it was but it was dark and not outside.
The kids themselves had their own monster things which they would ride and fight from. The character's outfits matched the colour of their monster, the girl I believe was purple and green, one boy was blue and another was either orange or red. The group definitely had one girl and two boys and I think maybe another boy?
I also seem to remember that what they were fighting had something to do with technology.
During the time the show aired it must have been sort of popular because the characters and their monsters were McDonald's Happy Meal Toys.