Multiple animation zones on 1 pixel strip with FastLED

It's hard to make sense of your attempt and why it failed when all we have to go on is your description.

But the line of code I quote here is a complete for statement with an empty body.

It will do nothing and leave no trace of having done nothing.

As such, it will probably be completely discarded by the compiler.

Semicolons. Can't live without them, strays can kill you.

a7