When lyx doesn't have the font for some tex commends it substitutes red text.
Do you have the package latex-xft-fonts installed? I think this should provide nice looking fonts for you. Perhaps lyx should depend on the package latex-xft-fonts so that it looks good by default. -- Math symbols not displayed, substituted with red TeX tags https://launchpad.net/bugs/68971 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
