This is a styling example in PlantUML:

    class TestClass {
      ""Monospaced""
      <color:green>Colored
    }

See here: https://plantuml.com/creole.

Regarding the comments, here's a PlantUML example:

    class TestClass {
      ""Monospaced"" ' comment not supported; displayed
      <color:green>Colored
    }

    class TestClass2 {
      ' comment supported
      Type varname ' comment not supported; displayed
    }
    ' comment supported
    foo::bar --> baz ' comment not supported; breaks diagram (!)