Neopixel Mode change with a button

Projects Programming
4

and each loop has a statement such as:

void rainbow(uint8_t wait) {
if (counter == 2) {
uint16_t i, j;

Seems backwards to me.

if(counter == 2)
   rainbow(20);

seems more straightforward.

I suspect that you want to increment counter when the switch BECOMES pressed, though, rather than when the switch IS pressed. Look at the state change detection example.