Delay and loop of a list

MIT App Inventor Help
1

I am making an app for my robot. Robot comes with LED-s. I want to include a feature that does a lightshow with LED-s. It's function should be to change all LED-s colors that are in a list. Currently it changes them one after another but in less then a second.

How to add delay between those changes?

Next, I want to loop it until I press the button again or turn the switch off.

How to make a loop like that?

2

You need a clock component.

3

Here's an example of how to use a global list with a Clock timer: