How can I change the background color of the dhx_diagram class?

Diagram
#1

The default background color is #f7f7f7f7.
How can I change it to white?
I tried the following styles but did not change.
.dhx_diagram {
    background-color: #ffffff !important;
}

#2

https://snippet.dhtmlx.com/pqzt4ctl
Seems to work well for me locally.

If the problem still occurs for you please, provide a compete demo or a demo link, where the problem could be reconstructed

#3

Thanks, I was able to try and solve the problem.