why doesn't fillcolor work with graphviz?

I am following the exact instructions from the graphviz documentation, but I am unable to add fillcolor to nodes.

Here is my graph:

digraph hello_world {
 node [href="javascript:void(click_node('\N'))"]
 node0 [label="No label",shape=box,width=0.75,height=0.75,fixedsize=true]
 node1 [label="No label",shape=box,width=0.75,height=0.75,fixedsize=true]
 node2 [label="No label",shape=box,width=0.75,height=0.75,fixedsize=true]
 node3 [label="No label",shape=box,width=0.75,height=0.75,fixedsize=true]
 nodeEdge0 [fixedsize=true,shape=diamond,label=".Nojjjj label.",fillcolor=red]
 node3 -> nodeEdge0 [arrowhead=none]
 nodeEdge0 -> node2
}

Still, the graph does not set nodeEdge0 to have a red background color.

Any ideas?

Solution 1:

add style=filled to the node

nodeEdge0 [fixedsize=true,shape=diamond,label=".Nojjjj label.",fillcolor=red, style=filled]