Conditional Formatting script issue

Hello everybody,

I am trying to change the color of my chart's columns depending on my measures (Nb total de factures, Nb factures P2P and Nb factures non P2P). Here is the result I would like to have:

I use the Conditional Formatting to do so:

Unfortunately, when I click on ok, the application Design Studio doesn't respond anymore:

After a while, a pop up asks me if I want to stop the script because it is slowing down my web browser:

No matter if I click yes or no, the application shuts down after a while (I am using the version 1.5 of DS). I tried to execute it with Chrome and IE, I also tried to reset my browser but it didn't work.

Does anyone know why and what can I do?

Thanks for your help!

Yann