How do I get the index of a container in a repeater and change the color per container?

@chidiejike Refer to the Repeater Documentation to see how to use Repeaters.

The Repeater is populated by using the data property, but you cannot modify the data array in-place using an index - $w(“#repeaterfill”).data[i] will not work.

The Repeater does not have a container property. Use the index parameter of the onItemReady() event handler to access each Repeater Item by it’s index (position) in the Repeater.