Imagining Allah Ta'ala

I know that Allah is noor/made of noor but it is not like the ordinary light. So I used to imagine a bright light that maybe we will see Allah like this. It was a 'what if' question. But then I forgot about it. I neither accepted nor rejected, is that kufr?

Moreover we studied at school that everything is created from the noor of Allah. Is that kufr too? Do I need to restate my shahadat? Because I probably thought that there is a possibility that he looks like this. Now I know that whatever we imagine him to be like, he is not like that. If these are not kufr, please tell in what circumstances would these assumptions turn into kufr.