legend of colors sometimes does not shown correctly

[Foina]

I have two questions. First, in my work, the second node's color is not shown on the legend of colors. Second, I do not know why sometimes the first node color shown is incorrect. My node color is based on the relation type. I have two types, but sometimes it only show one type.

[Foina]

I know what's wrong now. Because the second node does not show color in the legend when all the nodes are the second node the legend and colour will show in the wrong way. Is there a way to treat all the nodes as the first nodes?

[Foina]

I am using the version release supports Kibana 7.0 to 7.4