Hi Rawn,
The way i would do it.
Make an array with the color’s / backgrounds you want to be able to shown.
const array =
[{
image:imagesource1,
color:color1
},{
image:imagesource2,
color2
}]
Then as you load a page, generate a random number like @russian-dima said.
Be sure the random number isn’t higher then the array length
Then use that random number to select the a background/color and use it to change the page background.
$w("#page").background.src
Kind regards,
Kristof