Hi, I use nodes in many of my diagrams. When I do something like this:
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One first option is: skinparam defaultFontColor white node N as "My Host" #black
(see other options here http://plantuml.sourceforge.net/skinparam.html ) You can also individually change color setting: skinparam defaultFontColor white node N as "My Host" #black node N1 as "<color:red>My Other Host</color>" #black
You can have
http://www.plantuml.com/plantuml/uml/SoWkIImgAStDuShBJqbL01FAwKMfgNaArLmA2Yc99Ob9YSMf2hdvUUdv2if9EQMfNBLS3gbvAK0z0000