The actress just listed this 5-bedroom home in Sherman Oaks for a cool $2.55 million ... and the 4,500-square-foot home is awash in a sea of rainbow colors, rooms full of red roses and some over-the-top murals.

The gated property stands out with its hot-pink exterior and you're gonna have to trust us here -- but the interior is just as loud! It's got a rainbow staircase, a colorful mural running the length of a two-story wall, and some golden wallpaper ... just for good measure.

Bella's former master bedroom -- or is it a primary bedroom -- features a huge walk-in closet and a marble bathroom covered in ivy.

Another room is called the rose room, which you guessed it, is a hot-pink room covered in roses with a pink chair ... that dangles from the ceiling. For real.

Bella's backyard is pretty tame compared to the rest of the house ... there's a lush lawn surrounding the swimming pool and spa, with a built-in grill decking out the rest of the patio.