How to find or parse html tag with namespace?

Question

I'm trying to find custom html element with namespace but I could not get any success on it. I also checked other libraries like QueryPath, Ganon including phpQuery. Only PhpSimpleDom library can do this but I don't want to use it anymore. It's has memory problem and does not provide the full selector features.

Can anyone please help me on it?

See example below;

<plugin:color value="#000" />

Thanks in advance. Smac