The documentation is kind of lacking.
Could anyone explain the meaning of blue solid/dotted lines and red solid lines between words here?
How are they different from the dotted versions?
Looking into the source code, I see this but I don't understand the color code and the code itself.
Source: https://tug.ctan.org/macros/luatex/generic/lua-visual-debug/doc/lvdebug-doc.pdf