How to underline text as part of a label?

Question

Following is code using dot language.

subgraph cluster1
            {
            node[style=filled];
            color=blue;
            b0->b1;

            label ="Tada"; // I want this to show as underlined.
            }

Answer 1

You can use HTML-like labels and the <u> tag:

digraph cluster1
{
    node[style=filled, color=blue];
    b0->b1;

    label = <<u>Tada</u>>; // I want this to show as underlined.
}

This is the result:

Note that your color=blue statement wasn't applied to any element. I moved it into node.

As pointed out in the comments, this currently only works for svg output. I tried with png and pdf on my Mac running 10.14.6 and they weren't underlined.