How to change the background colour of logos

I am using a template that contains these stock logos. However, after replacing a stock logo with my own, the background behind it remains black. See below:

I cannot see any option to change this colour from black to transparent. Does anyone know how to do this?

Thanks.

Hey Marek,

have you thought about adding this preset again? Since you want to change the logos anyway? It looks like this then with a white background…

Also, you can change the background here: