The Wonderland Board

I am at the start where I met the rainbow-stars
Levelname: Here and there and back again

Would somebody please tell me how to get that rainbow-key?
I can't figure it out
If I go through the indigo transporter and stand immediately on the switch, I can't get to the key...
And if I just run to the key, I have no time left to stand on the switch.

Never mind, I figured it out
But if somebody wants to know: stand on the switch and immediately run to the key.

Yes, that took me a looooonnngg time to figure out.

Yes, you must run through the teleporter while it is collapsing, before it changes to the new color. Tricky. The first time I did it I was so happy I forgot the key.

https://www.youtube.com/watch?v=Loz2mLai4oU
Here is it.