Hi, i have to do a random change of background colors, previous selected by this four switches. I am using two screens. On the first i have the switches and after you click the button, you go to the second screen where the colors have to be changed. How can i do?
Hi @ALEX_ANTONPIO_NOTORE, welcome to the Thunkable community! 
Do you have to use switches? Have you considered using sliders instead??
Is there a way to select single colors?
This can be done. Instead of a random number generation block, use a numeric block with the desired color value.
Color can be set as follows
or
#ff0
#f0f8
hsl(200, 100%, 50%)
hsla(200, 100%, 50%, 0.1)
rgba(0,0,0,0) or “transparent”.
The app now works, thank you