This map features flashing lightning and rainfall effects.
-To toggle the lightning effect, click the BG2 button
-To toggle the rain effect, click the FG1 button
Interestingly, unlike the main level area and bonus #1, DK and the other objects in bonus #2 aren't assigned a "night" palette. Perhaps in whatever far-up area this bonus takes place, the clouds are starting to clear, and the sun is beginning to peek over the horizon? That or the level designers got lazy. ;)