"Column" element : using 2 different colors for headers = more clarity

Hello !

I've been creating some activities using the "column" element in order to aggregate different H5P content types to study an excerpt from french literature. When I am in admin mode it is very difficult to find my way among all the activities that I've created and piled up with the "column" element because all the headers are coloured with the same color (the famous "H5P blue" ;)) including headers inside a content type. The hierarchy between my different activities is not very easy to pinpoint ; editing or redordering my contents proves to be very uneasy.

Here is the content that I've created : 

Here is an overview of the same content when I am in admin mode (all headers are in blue, I have no clear view on the different content types that I have used and piled up) : https://monosnap.com/file/NW3OQcxLkEiqI4xBh5I9IWipFT2bVb

My request would be to use two different background colors : the actual "H5P blue" may be used in the main header (the header of the content-type) and another blue (clearer blue maybe ?) could be used the different headers inside a content-type. It could come out like this :

https://monosnap.com/file/0vwz8UdgI9V3IEdoWpgS2I653OGQea

Sorry for the messy english !

thanks !

Isabelle