PL9823 LEDs light up white only.

Hello all,
I have now bought the PL9823 and an Arduino Pro Micro for Simhub. Now when I connect the LEDs, all the LEDs just light up plain white. Also when I close the Simhub software nothing changes and they just glow white. I actually did everything right when setting up the Arduino in Simhub.

Does anyone have any idea what the error could be?

Thanks in advance!